LBAH Informational Articles

Kidney Disease (Chronic Kidney Disease) or Chronic Renal Failure

One of the more common conditions encountered in pets, especially as they age, is kidney (renal) disease. This disease is particularly prevalent in older cats, and is called chronic kidney disease (CKD). It is also known as chronic renal failure (CRF). Once a pet has CKD the changes in the kidney are irreversible, so it is important to catch this disease early to mitiage its progression.

25% of the blood ejected from the heart on every heartbeat goes directly to the kidneys, a testimonial to how important the kidneys are to health. When a pet has chronic kidney disease there are many issues that need to be addressed for a successful outcome. You will learn about them in more detail later in this page. The more important ones are:

  • Protein and phosphorous regulation
  • XS protein in the urine
  • Elevated creatinine in the bloodstream
  • High blood pressure
  • Anemia
  • Dehydration and electrolyte imbalance
  • Low pH in the bloodstream
  • Stomach and intestinal ulcers

We use the IRIS (International Renal Interest Society) system of classification at the Long Beach Animal Hospital to better diagnose and treat CKD. IRIS is a group of veterinary kidney specialists throughout the world that have studied this disease extensively and have set standards for diagnosis and treatment. At the end of this page there is a link to this organization for more information on how they stage kidney disease.

The IRIS system stages kidney disease in dogs from Stage I to Stage 4. We want to catch those dogs that are at Stage I so we can initiate treatment then and have a much better outcome. In this staging system we are closely monitoring several important parameters:

  1. Creatinine trends
  2. Protein in the urine
  3. Blood Pressure

urinalysis-protein-cat

This cat has a normal creatine, so the kidneys seem OK on the blood panel. The urinalysis shows a protein level of 1+. This could be the sign of CKD in this cat, and should be treated early if further tests indicate it does have CKD. Just changing to a food like Hills K/D can make a big difference on a cat like this if started early in the course of the disease, and before other problems related to CKD appear. 

In addition to these parameters, the following general parameters are also checked for early signs of chronic kidney disease. These parameters are also used to monitor progression and success of treatment:

  1. Small kidneys on abdominal palpation
  2. Radiographic or ultrasound evidence of small kidneys
  3. Decreased urine specific gravity

This page describing kidney disease is very thorough with significant information on anatomy, physiology, and pathophysiology. We have information on treatment towards the end of this page if you want to bypass all the background information and skip right to it. We also have a summary page on kidney disease if that better suits your needs.

Cats that have kidney disease commonly have other problems that need careful attention if the kidney problem is to be treated successfully. Some of these other common problems are hyperthyroidism, heart diseasedental diseasesugar diabetes (diabetes mellitus), and high blood pressure (hypertension) leading to blindness.

Several medical terms are used when describing kidney disease:


Renal anatomy

The kidneys are such a vital organ that 25% of the blood that enters the circulatory system from each heartbeat goes directly to the kidneys through the renal artery. With such a high metabolic rate the proper functioning of this organ is critical to health. The high metabolic rate and importance of this organ makes the kidneys susceptible to many problems.

This is the kidney from a cat, with the fat that normally surrounds it removed. It lies in a depression in the abdomen called the retroperitoneal area. You can see the dark liver on the far left, and the renal vein as it leaves the kidney and mergers with the vena cava. The blood from the vena cava flows into the liver and then directly to the heart. This is the blood that has been filtered of impurities and is reentering the circulation. You can not see the renal artery or ureter, they are buried in the white fat at the top of the kidney.

This is how it normally resides, protected by fat in the abdomen

OLYMPUS DIGITAL CAMERA

Blood enters the renal artery and flows into the nephron where it is filtered. The blood from the renal artery that has been filtered now flows out of the renal vein where it goes back into the circulatory system. The impurities that the nephron filters out of the blood collect in the renal pelvis and eventually out into the ureter in the form of urine.

The primary functional unit of the kidney is the nephron. Each kidney has upwards of one million nephrons, so obviously they are microscopic in size. Every nephron is a self contained unit that can form urine by itself. Not all nephrons are used at the same time, which gives the kidneys the capacity to increase their workload if called upon. This reserve capacity is lost when chronic renal failure occurs. These pets (especially cats) outwardly appear normal, but have greatly reduced ability to adapt to changing physiologic needs. Being chased by a dog, not having enough water to drink, etc., can send them into renal failure.

This is how it looks in a real kidney from a cat

This is a kidney, turned sideways compared to the one above, as we view it with the ultrasound. The yellow line is measuring its length.

The important anatomical components of the nephron are described below:

  • Afferent Arteriole

    This small artery is one of the many small branches that come off the renal artery as it enters the kidney. It supplies the glomerulus with blood. Eventually filtered blood returns to the renal vein.

  • Glomerulus

    This is a collection of many small blood vessels at the end of the afferent arteriole. Normal pressure of the blood in the glomerulus causes fluid to flow into a collecting area called Bowman’s capsule.

  • Bowman’s Capsule

    Fluid that collects in Bowman’s Capsule eventually flows into the tubules. It is in these tubules that waste products and excess electrolytes are filtered out of the fluid, and normal blood constituents like protein and glucose are absorbed back into the bloodstream. When a diuretic like Lasix is given it acts on these structures.

  • Collecting Ducts

    At the end of the tubules is the collecting duct, where the urine produced starts to flow out of the nephron. Other nephrons deposit urine in collecting ducts as these ducts flow into the renal pelvis. From the pelvis the urine flows into the ureter and bladder.

The kidneys are located in a specific area of the abdomen called the retroperitoneum. This area is a small indentation at the top of the abdomen just underneath the spinal vertebrae. It affords protection to this vital organ.

Renal Physiology

The kidneys have a profound affect on almost all the physiologic processes of the body. The mechanism by which the kidneys perform these functions is extremely complex, the most important of which will be summarized:

  • Fluid Regulation

    In relation to the kidneys, the brain monitors bloodstream levels of water, waste products, electrolytes, and red blood cells. The circulatory system also has receptors like the brain to monitor blood volume also. If the water level is too low, as occurs with dehydration, the brain secretes more of a hormone, called ADH (anti-diuretic hormone), into the bloodstream.

    As a result, the kidneys excrete less water into the urinary tract, retaining more fluid in the bloodstream to counteract the dehydration. The brain also increases thirst simultaneously. The end result is less urination. The urine that does get excreted is more yellow than usual due to a greater concentration of waste products being excreted in relation to the amount of water being excreted. The only thing we notice is that we urinate less and it is more yellow in color.

    As we drink water to quench our thirst and rehydrate, the body notes this change and the brain secretes less of the hormone called ADH. Now when we urinate more water is excreted by the kidneys, and our urination occurs with a dilute urine in greater quantity. So, the ability to concentrate the urine and dilute the urine is an important function of the kidneys. It is a fine tuned mechanism that is closely regulated to maintain optimum amounts of fluid in the bloodstream and organs.

    As a fun fact, it is the inhibition of ADH by alcohol’s depression effects on the brain that causes excess urination when drinking alcoholic beverages. Eventually this excess urination causes dehydration, leading to that inevitable curse called a hangover.

    The kidneys also secrete a hormone called renin. Through a complicated set of biochemical pathways this ultimately leads to an increase in salt (sodium) in the bloodstream. Sodium pulls water towards it, so more sodium means more fluid in the bloodstream. It will have an effect on blood pressure, which you will learn about later.

  • Waste Product Regulation

    The brain also monitors waste products that build up in the bloodstream. These waste products are the end product of normal metabolic processes, especially the metabolism of proteins. They are called nitrogenous waste products, and are measured by a blood parameter called blood urea nitrogen (BUN). Another waste product that is closely regulated by the brain and kidneys is called creatinine. It is the end product of the metabolism of muscle.

    The kidneys also excrete toxins and foreign substances that are introduced into the body. Almost every medication given, either orally or by injection, is eliminated to some degree by the kidneys.

    The rate at which fluid flows into the glomerulus is important. This is called the glomerular filtration rate (GFR), and is measured in ml/minute. Too small a flow and waste products are not eliminated, a problem encountered during dehydration. Too much flow and normal blood constituents like protein are excreted when they shouldn’t be.

  • Electrolyte Regulation

    Electrolytes are also of importance in relation to the kidneys. Sodium is of extreme importance in the normal functioning of all cells. It allows nerve impulses to occur and is critical in the regulation of water levels in the bloodstream. Through the release of a hormone called angiotensin the kidneys regulate fluids levels of sodium in the bloodstream. This has a major affect on the blood pressure. Potassium is also a critical electrolyte. Potassium levels need to be kept at a very narrow range to prevent serious consequences like heart irregularities.

  • Hormone Regulation

    The kidneys also regulate calcium and phosphorous by hormones called calcitrol and parathyroid hormone, and by regulating vitamin D. Vitamin D allows the absorption of calcium from the intestines. If the kidney disease progresses long enough the excess secretion of parathyroid hormone causes the bones to become swollen and fibrous as the body attempts to maintain a normal calcium level. This is called renal osteodystrophy.

    As the bones become more fibrous the marrow is not able to produce red blood cells as effectively. This leads to weak and thin bones, as evidenced by a swollen face and jaw as the bones of the lower jaw weaken. It can occur in other bones also. This is similar to what occurs in reptiles when they get bone disease. You can see a picture of the swollen jaw of an Iguana with bone disease. Don’t forget to come back here because we are only just getting going.

  • Acid-base Regulation

    The pH of the bloodstream, which is a measure of acidity, is another important area of kidney physiology. The kidney regulates this acidity by excreting excessive hydrogen ions and the selective secretion and reabsorption of bicarbonate.

  • Red Blood Cell Production

    The kidneys secrete a hormone called erythropoeitin into the bloodstream. This hormone circulates to the bone marrow and stimulates it to produce red blood cells. A lack of adequate levels of this hormone will cause anemia. Toxic waste products that build up in the bloodstream decrease the life span of a typical red blood cell, further exacerbating the anemia. And, as you already learned above in hormone regulation, the fibrous bones have less bone marrow. There can even be clotting problems due to a low number of platelets.

Pathophysiology of Chronic Renal Failure

Over the course of days, weeks, or months, normal nephrons get replaced with scar tissue, and become nonfunctional. In chronic kidney disease (CKD) this scar tissue is a result of excess phosphorous. When this scar tissue occurs to approximately 75% of the nephrons the kidneys no longer have the ability to respond to the needs of the body. There is no longer any reserve, and all of the remaining nephrons are working full time. These remaining nephrons swell (called hypertrophy) to adapt to this increased workload. This allows them to adapt and selectively excrete or reabsorb important nutrients.

Eventually these remaining nephrons cannot keep up, and it leads to a buildup of nitrogenous waste products (called azotemia) in the bloodstream. The body compensates by increasing thirst, which causes PU/PD, and the waste products get flushed out of the bloodstream and into the urine.

Unfortunately, flushing out the waste products in bloodstream with excess thirst also flushes out important electrolytes and protein into the urine. This causes weight loss and weakness as the kidneys continue to deteriorate. The excess urination that occurs as the body tries to rid itself of these excess waste products can also cause dehydration.

Oral ulcers occur when bacteria in the mouth convert the extra uremic waste products to ammonia. Waste products that buildup in the bloodstream also have an effect on the bacteria in the mouth and exacerbate gingival and periodontal disease. The waste products also change the pH of the bloodstream and cause ulcers in the stomach and intestines. This causes vomiting (emesis), loss of appetite (anorexia) and weight loss. Ulcers can also be found in the mouth and tongue due to the uremia.

Hormones are affected and phosphorous builds up in the bloodstream further adding to a pet’s woes. Eventually calcium is deposited in abnormal places, and can lead to problems with many skeletal and internal organ problems. Due to sodium imbalance, hypertension (high blood pressure) can develop. Hypertension occurs in a high percentage of animals with kidney disease.

As the kidneys continue to deteriorate erythropoetin is not secreted in adequate quantity and anemia results. This anemia also makes a pet weak and adds to the anorexia that is usually present.

The nervous system is affected by all of these problems. If the uremia is severe enough hypothermia and seizures can result.

Classification

  • Acute Renal Failure (ARF)

    This is a serious form of kidney disease that commonly leads to death. The kidneys have an abrupt decrease in the GFR due to a toxin or loss of adequate blood supply (called ischemia). Many different disease processes can cause ARF, including anesthesia for any surgical procedure. That is why we give intravenous fluids (IV) to almost every surgical case.

  • Chronic Renal Failure (CRF)

    This is the most common form of kidney disease we encounter, particularly in older cats. It tends to develop more slowly than ARF, so the body has time to institute corrective factors (called homeostasis) to compensate for the problem. Unfortunately, these corrective factors tend to hide early symptoms of disease. Consequently, treatment is not initiated as soon as it might be. Again, as in many diseases we encounter, this drives home the fact that pets over 8 years of age should have annual physical exams along with blood and urine samples.

    Pets in CRF that have lost their ability to compensate for their failing kidneys can be presented to us in an acute phase, similar to ARF.

Cause

The are a multitude of causes to kidney disease. Some of these cause ARF, while others cause CRF. In some cases, ARF can progress to CRF.

Toxins

Many drugs that are used on a day to day basis can be toxic to the kidneys:

  • snake and bee venom
  • antifreeze
  • pesticides
  • herbicides
  • solvents
  • heavy metals
  • cancer chemotherapeutic agents
  • aspirin and antinflammatories
  • anesthetics
  • anti parasite drugs
  • antibiotics
  • blood pressure medication

The outcome of exposure to these toxins depends on a pet’s age, other disease processes that might be present, any medication your pet is currently taking, how long there has been an exposure and at what dose, along with the specific toxin. In some cases they are treated with supportive care like intravenous (IV) fluids. Other cases are treated with specific antidotes.

Some toxins, notably antifreeze ( 95% ethylene glycol) are catastrophic to the kidneys. Antifreeze is very sweet tasting and is readily licked by both dogs and cats if it spills on the ground when car antifreeze is changed. Ethylene glycol is converted in the liver and kidney to a toxic metabolite that changes the pH of the bloodstream and destroys the kidneys by depositing calcium oxalate crystals in the renal tubules.

It is a medical emergency and requires specific and immediate measures if the kidneys are to be saved. Unfortunately, unless a pet owner actually observes their pet licking antifreeze, they don’t bring their pet in for care until it is very ill. In this situation the prognosis is grave, and death is common. If treated within a few hours of ingestion the prognosis for recovery is much better.

This disease has several distinct phases:

    • Stage I

      This occurs during the first 12 hours after ingestion. Pets will vomit, drink and urinate excessively (PU/PD), and appear intoxicated. It is at this stage that observant owners might bring their pet in for an exam.

    • Stage II

      This stage occurs 12-24 hours after ingestion. Symptoms are vague and pets appear to recover.

Stage III

  • This stage appears 24-72 hours after ingestion. Pets in this stage are severely depressed, are not eating, are vomiting, and are not producing urine. When this stage appears death is imminent.

Treatment needs to be given early in the disease to be effective. Inducing vomiting and flushing the stomach out can be very helpful if performed within 1-2 hours of ingestion of antifreeze.

Intravenous fluids and diuretics are also given to maintain normal kidney function by keeping an adequate GFR. Sodium bicarbonate is given to maintain a proper pH of the bloodstream.

Antidotes are given and can be highly effective if given early enough. In cats we give them ethyl alcohol (vodka) intravenously, and literally make them drunk. The vodka prevents the liver from converting the ethylene glycol to the toxic metabolites that destroy the renal tubules. This treatment is used in dogs also.

A better antidote, that works in dogs only, is called Antizol. It is an expensive medication, but it can literally save your dogs life.

Fortunately, the antifreeze manufacturers have added a bitter taste and we do not see this disease anywhere near as commonly.

Cancer

Cancer of the kidneys can occur even at a young age, although it is usually diagnosed in older pets. Sometimes it arises from the kidneys (primary), much more often the cancer has spread to the kidneys from a different organ (secondary or metastatic). When primary cancer does occur it is often malignant. Fortunately, primary renal tumors are rare. Cancer of the kidneys occurs more in cats than in dogs. Click here to see a case study of how we diagnosed and treated kidney cancer in a dog.

Primary

  • Lymphosarcoma- Tthis is the most common renal tumor in the cat. Cats with renal lymphoma are commonly positive for the FeLV.
  • Adenocarcinoma- The next most common renal tumor in the cat
  • Transitional cell carcinoma
  • Nephroblastoma
  • Adenoma
  • Fibroma

Secondary

Poor Perfusion

Poor perfusion means inadequate flow of blood through the kidneys, which decreases the GFR. This lack of blood flow prevents the kidneys from eliminating waste products and toxins buildup in the bloodstream. This lack of perfusion is the main pathology leading to ARF.

Heart Disease – If the heart is weak it can not pump enough blood to the kidneys to keep them properly perfused.

Drugs – Some medications can cause constriction of the artery to each kidney with a resulting lack of perfusion

Dehydration – Inadequate fluid in the circulatory system will cause poor perfusion. Dehydration is the most common cause of poor perfusion.

Cysts

They can put pressure on normal kidney tissue and compromise the filtering ability of the nephron. These tend to be found in older male cats. When there are no symptoms they are sometimes found accidentally when checking for other problems. This is called an incidental finding. When symptoms are present, they can be mild and treated easily by drainage, or there might be compromise with the normal filtering ability of the kidneys.

A specific form of cyst, called Polycystic Kidney Disease (PKD), is inherited in Persian and other long haired cats. Cysts will occur in both kidneys and will lead to CRF eventually as they enlarge and decrease functional renal tissue. The best way to make this diagnosis is with ultrasound. Ultrasound should be used on the offspring of adult cats with PKD and before any symptoms appear.

Immune System Diseases

Bacteria, viruses, cancer, and diseases of internal organs can all set off a reaction where the immune system can interfere with the ability of the kidneys to filter properly. This is sometimes called glomerulonephritis. Symptoms range from mild early in the disease to all the signs associated with kidney failure. A common method of diagnosis is excess protein in the urine (proteinuria) and a lack of protein in the bloodstream (hypoalbuminemia).We use ultrasound at our hospital to help in this diagnosis.

Treatment depends on the exact cause. It might include anti-immune system drugs, aspirin, dietary change, medication to decrease blood pressure, salt reduction, IV fluids, and diuretics.

Parasites

There are 3 main parasites that invade the urinary tract and affect the kidneys:

    1. Capillaria plica

      They are threadlike worms that affect the kidneys, bladder, and urethra. Eggs of this worm that are passed in the urine are eaten by earthworms, which are then eaten by dogs to complete the cycle. In some dogs there are no symptoms, while in others there might be blood in the urine (hematuria), difficult urinating (dysuria), or urinating small amounts (pollakuria). This parasite is diagnosed by finding the egg in a urine sample. In most cases the disease goes away by itself within 4 months, although it can be treated. Prevention of recurring cases relies upon removal of surfaces that could harbor earthworms.

    2. Capillaria feliscati

      This is an uncommon parasite in our area that invades the urinary bladder of cats. Usually there are no symptoms, and the disease routinely resolves by itself within 4 months.

Dioctophyma renale

  1. This parasite resides in the kidney or abdomen near the kidneys, although they have been found in the urinary bladder, urethra, ovary, uterus, and pericardium. It causes a gradual deterioration of the kidneys.Eggs from this parasite are passed through the urine and eaten by aquatic annelids. Dogs get this parasite from eating raw fish and frogs that have eaten the aquatic annelids.Sometimes there are no symptoms until there has been significant kidney destruction. They are diagnosed by finding the egg of the parasite in abdominal fluid or in the urine. Treatment involves surgical removal of the worms from the kidneys or abdomen.They are difficult to control because the eggs can live in the environment for a long time. Dogs should be prevented from eating frogs and raw fish. It is possible for humans to get this disease from eating raw fish or frogs also.

Viruses

The FeLV and FIP can affect the kidneys. These viruses are prevalent in the cat world, and cause significant problems. We do not see these diseases commonly any more, especially FeLV. This is a testament to the use of vaccines.

Bacteria

They can ascend from the lower urinary tract and cause dysfunction in the kidneys. Leptospirosis is a specific bacteria that affects the kidneys, seen almost exclusively in dogs. Dogs get it by direct contact with infected urine through their mucous membranes. It also affects the liver.

In severe cases a dog can go into shock and rapidly die from Leptospirosis. In some cases they are sick with a fever, depression, vomiting, diarrhea, and poor appetite. There might also be muscle pain, eye problems, and respiratory problems. Most cases are chronic and might not show many symptoms.

There is a vaccine to prevent this disease which is a routine part of our DHLPP vaccine. The vaccine is highly effective in preventing this disease.

Bacteria can also cause pyelonephritis, an infection of the renal pelvis. The following bacteria are implicated:

  • E. coli
  • Staph. aureus
  • Proteus mirabalis
  • Strep. spp.
  • Klebsiella pneumonia
  • Psuedomonas aeruginosa
  • Enterobacter spp.

These bacteria usually ascend from the lower urinary tract. Occasionally they enter the kidney from the bloodstream. Their presence can cause constriction of the blood supply to the kidneys and destroy normal kidney tissue when attacked by the immune system. They can eventually lead to kidney failure. It is important to culture the urine for bacteria in any pet that is diagnosed with CKD because of the damage these bacteria can do to the urinary tract.

These bacteria can cause ARF or CRF. Symptoms include fever, depression, lack of appetite, pain, PU/PD, and weight loss. In the chronic version sometimes there are no symptoms at all. They are treated with antibiotics for a minimum of 4 weeks, along with supportive care.

Amyloid

This is the deposition of fibrous protein cells in the glomerulus that interfere with the kidneys’ ability to filter. Amyloid causes the kidneys to become small and irregular. Pets with amyloidosis have typical symptoms of kidney disease.

Most dogs are middle aged or older, and it is seen in abyssinian cats and Shar Pei dogs. It is diagnosed by proteinuria, just like the immune system diseases that affect the kidney. Amyloid can be deposited slowly allowing a long life, or it can occur rapidly leading to early death. There is no specific treatment except routine supportive care of the kidneys.

Trauma

One of the more common causes of kidney trauma is when a pet is hit by a car. These injuries can be serious and easily lead to death. Radiography is helpful in making this diagnosis, although special x-rays or ultrasound might be needed to know for sure.

This is a bruised kidney from a cat that was attacked by a dog. The bruise covers over 1/3 of the kidney. This is a fatal lesion.

Symptoms

The symptoms that occur depend mainly on how long the problem has been present and the specific reason the kidney failed in the first place. Some of the more common ones you might notice at home are:

  • Excess urinating and drinking

    This is known as polyuria/polydypsia (abbreviated PU/PD). It is by far the most consistent symptom of kidney disease. PU/PD also occurs in sugar diabetes and hyperthyroidism to name a few, so the diagnostic process needs to be followed to make an accurate diagnosis of a pet with symptoms of PU/PD. If you suspect your pet of having PU/PD you should measure how much water it drinks each day and look for a changing trend.

    In ARF there might not be any urination (called anuria) at all. This is an extreme emergency. Two of the more common causes are antifreeze poisoning and male cats with urinary tract disease that have a plugged urethra.

  • Weight loss

    Weight loss occurs due to poor appetite and the loss of protein as the kidneys attempt to flush toxins out of the body.

  • Poor appetite (anorexia)

    The buildup of toxins, electrolyte imbalances, dehydration, and even anemia are the causes of a poor appetite in kidney disease. This is one of the most common reasons pet owners bring their cats to us when renal failure is the cause. Ulcers in the mouth and stomach add to this problem. Sometimes its a wonder that cats with moderate to severe kidney disease even eat at all.

  • Weakness

    Dehydration and poor appetite add to weakness. An imbalance of a specific electrolyte called potassium adds significantly to weakness. This is the reason we sometimes add supplemental potassium to the fluids we give pets with kidney disease and also why we supplement them with oral potassium.

  • Vomiting (emesis)

    The buildup of toxins is a big cause of the vomiting. Vomiting causes further dehydration and loss of potassium, further exacerbating the problem in pets with kidney disease.

  • Seizures

    If uremia is severe enough the brain can be affected by the toxins that build up.

  • Ulcers

    If the waste products are not being eliminated adequately the buildup of toxins can cause ulceration. These ulcers are prevalent in the digestive system, especially the stomach, and might necessitate medication.

    The tip of the tongue of this cat has an ulceration due to kidney disease. Oral ulcers are due to the breakdown of urea present in saliva to ammonia by bacteria found in the mouth. There are other causes of ulceration, including trauma, biting electrical cords, poisons, and viruses.

Blindness can occur due to the high blood pressure (hypertension) that develops as a consequence of CRF. We start therapy in cats when the systolic blood pressure consistently exceeds 160 mm Hg. Diastolic blood pressure is of no clinical use in the cat.

It can be difficult to get a consistent blood pressure reading in cats due to their stressful nature at our hospital. We will repeat the test numerous times, in a calm and quite environment, to make sure the readings are accurate.

The dilated pupils from this 15 year old cat with CRF are due to blindness.

Checking a cat for high blood pressure (called Hypertension) is not as simple as in a human. Specialized equipment is needed, including a doppler ultrasound.

Diagnosis

Since the symptoms of kidney disease mimic the symptoms of other diseases a thorough approach is needed to differentiate them. In every disease we encounter we follow the tenet’s of the diagnostic approach to ensure that we make an accurate diagnosis,  and also so that we do not overlook some of the other diseases that are also encountered in pets that have renal disease. Unfortunately, it is difficult to diagnose acute renal failure early in the course of disease.

Signalment

Kidney disease can occur at any age. If it occurs at a young age we tend to think more of toxins, cysts, and trauma. The most common form of kidney disease, CRF, occurs mostly in older pets.

Several feline breeds are prone to getting CRF as they age:

  • Siamese
  • Persian
  • Abyssinian
  • Burmese
  • Maine Coon
  • Russian Blue

Certain canine breeds are also prone to CRF:

History

Kidney disease is suspected in any pet that has some of the symptoms described above, especially PU/PD. The recent administration of medication, a recent bout of a disease, the changing of antifreeze, especially in the fall , and recent administration of anesthesia, are all helpful clues. Pets that have other diseases that can affect the kidneys, notably heart disease, and hyperthyroidism, alert us to the potential for kidney disease.

Physical Exam

Symptoms noted during a physical exam depend on what caused the kidney’s to fail, how long the disease process has been present and whether a pet has the acute form or chronic form of the disease.

Physical exam findings might include:

  • Pale gums due to anemia. You can check for pale games at home. Our Learning Center shows you how.
  • Dehydration
  • Small and irregular kidneys upon abdominal palpation if CRF is present
  • Large or nodular kidneys if a cyst or cancer is present
  • Underweight
  • Enlarged lymph nodes
  • Dilated or uneven pupils
  • Weakness

This older cat has kidney disease causing low potassium (hypokelemia). If the low potassium is severe enough a cat might have this neck posture.

Diagnostic Tests

Kidney disease can only be diagnosed with appropriate tests. As a general rule, we recommend screening for kidney disease by running a blood panel and a urinalysis on all pets greater than 8 years of age. We also screen for other diseases, notably liver disease, sugar diabetes, and hyperthyroidism, on this blood panel due to their prevalence in older pets.

Lymph node biopsy

Peripheral lymph nodes can be palpated in numerous locations. They can enlarge for several reasons, one of the more important ones is cancer. If they are enlarged and significant disease process is suspected then one of them is biopsied (example to follow).

Blood Panel

An important tool in the diagnosis of kidney disease is a blood panel. We look for abnormalities in several specific tests:

  • CBC- Complete Blood CountThis test checks the red and white blood cells. It is not uncommon for a pet with chronic kidney disease to have anemia.

    Anemia is noted in this pet by the low HGB (Hemoglobin) and low HCT (Hematocrit). This is mild, it can be much more severe than this.

    Ferret-AnemiaBloodPanel

  • BUN- Blood Urea Nitrogen – The BUN is usually elevated in pets with kidney disease. It can also elevate in dehydrated pets and in pets with an obstructed urethra causing an inability to urinate.If a urinary obstruction is the cause of an elevated BUN, called post renal uremia, the BUN levels tend to be extremely high. If dehydration is the cause of the elevated BUN, then the values do not tend to be as high. The BUN must be interpreted in conjunction with a urine test called specific gravity to know if the BUN is elevated due to kidney disease or dehydration. Liver disease and nutrition can also influence the level of BUN.
  • Creatinine – It is a very accurate way to diagnose kidney disease, and is more reliable than BUN since factors like dehydration are not as influential on creatinine as they are on BUN. This test is also a good early indicator of kidney disease even when normal if the trend in values is increasing. This again emphasizes the importance of yearly wellness exams as your pet ages. If the creatinine is going up, even if in the normal range, we might  start treating for a kidney problem much earlier in the course of the disease.
  • h4>Phosphorous
    In the more advanced stages of kidney disease the phosphorous levels elevate. This is not a good prognosis.
  • Amylase

    This is an enzyme produced by the pancreas to aid in the digestion of carbohydrates. It is excreted by the kidneys, so an excess in the bloodstream could indicate kidney disease

  • SDMA

    Serum symmetric dimethlyarginine is a new kidney marker that might aid in early diagnosis of this malady. Increases in this test occur prior to increases in serum creatinine if a normal creatinine is considered 2.4 or less.

  • Red Blood Cells

    The kidneys produce a hormone called erythropoeitin that stimulates the bone marrow to produce red blood cells. Anemia occurs in kidney disease due to inadequate levels of erythropoietin, shortened survival time of red blood cells in general, bleeding in the stomach or intestines, and the effects of uremic toxins on parathyroid hormone. Pets that are dehydrated might not show anemia on a blood sample until they are rehydrated.

    This dog has white gums in addition to the severe dental disease that is present. The white gums are due to anemia from CRF.

    This is an actual blood panel from a typical pet with severe CRF. The 3 most important tests on this panel are highlighted in yellow, along with their normal values on the right.

    This cat is even worse!  Click on it to see the details. It shows just how advanced this problem can become in cats before owners bring their pet in for treatment. We need to catch this problem long before it gets to be this severe and there is little we can do.

    CRF-SevereAzotemia

Urinalysis

This is also an important tool in the diagnosis of kidney disease and another early indicator of kidney disease along with creatine. Changes in several parameters could indicate kidney disease:

Specific Gravity (S.G.)

The ability of the kidneys to dilute and concentrate the urine is an important parameter to monitor. Water has a specific gravity of 1.000. A pet with kidney failure has a specific gravity of between 1.008-1.012. A specific gravity in this abnormal range is called isosthenuria. In cats with normal kidney function, the S.G. should be greater than 1.035, in dogs it should be greater than 1.025.

This number is interpreted in conjunction with the BUN to help determine if the elevation in BUN is due to dehydration or kidney disease. To complicate things further, dehydration and kidney disease can occur simultaneously. Also, as mentioned above, liver disease, a common problem in older pets, can also be an influence. To be accurate the specific gravity should be checked immediately after obtaining a urine sample.

Protein

Excess protein in the urine, called proteinuria, is a common finding in CRF. It can also occur in glomerulonephritis, pyelonephritis and amyloidosis. There is evidence to suggest that urine protein:creatinine ratio can be a predictor of survival time. Cats with a ration < 0.4 tend to live significantly longer than cats with a ratio > 0.4.

Cells

Specific types of cells, called casts, can also be an indication of kidney disease.

This urine sample is from the cat with the blood sample shown above. The S.G. is very low, and since this cat has a high BUN, the problem is most likely due to CRF. Fortunately for this cat there are no other serious abnormalities on this urine sample.

Urine Culture and Sensitivity

If pyelonephritis is suspected, or bacteria are noted in the urinalysis,  the urine should be cultured to determine which bacteria if any is present. If a bacteria is grown out then the appropriate antibiotic should be used for 4-6 weeks.

Radiography

Radiography can be very helpful in the diagnosis of kidney disease. It allows us to visualize the kidneys, check for stones in the urinary system, look for calcification that might go along with kidney disease, and also look at other organs that commonly have a problem as pets age.

These kidneys have a normal size and shape. Use this for comparison purposes as you look at the other radiographs.

This is the radiograph of a cat with normal kidney’s that is laying on its right side. The right kidney (RK) usually lies forward in the abdomen compared to the left kidney (LK). The area of the 2 kidney’s that overlaps is more whitish in nature.

This is the radiographic of a cat with renal lymphosarcoma (malignant cancer). The diseased kidney is the large white circular area in the center of this view. It is pushing the large intestine down. Here is different cat with renal lymphosarcoma. It is a different view from the one above. Both kidneys ( K ) are involved in this cat.

Ultrasound

A very valuable tool in the diagnosis of kidney disease is ultrasound. It allows us to look at the ureters and bladder, internal anatomy of the kidney, measure kidney size, and take a biopsy for an accurate diagnosis. In many cases the use of ultrasound precludes us from having to perform an exploratory surgery.

These ultrasound pictures are from the first cat above with the enlarged kidneys. The first picture shows a normal right kidney. Its measurements are 2.3 cm by 3.6 cm.

The 2nd image shows the large and cancerous kidney, measuring 4.6 cm by 7.3 cm. A biopsy was taken from this kidney to confirm the diagnosis of renal lymphosarcoma.

Excretory Urogram

This special test, also know as an IVP (intravenous pyelogram) gives us significant information about the renal system. It has to be used carefully if ARF or CRF is suspected because it can exacerbate the problem. A radiopaque dye is injected into the bloodstream and radiographs are taken of the dye as it passes through the kidneys, ureters, and bladder.

This picture shows how the dye outlines the center of each kidney, called the renal pelvis (remember the renal pelvis in the anatomy picture at the beginning of this page?).

Laparotomy

Exploratory surgery (laparotomy) is frequently used as an aid in the diagnosis and treatment of renal disease, especially cancer. We use this option when we feel that ultrasound will not be advantageous.

The arrow points to a lump on the surface of a kidney. It was caused by cancer that spread from the stomach. A section of the lump was biopsied during surgery to determine the cause. The tremendous blood supply to the capsule that surrounds kidneys can easily be visualized. Even though this capsular blood supply is extensive, it pales in comparison to the amount of blood that flows into and out of the kidneys through the renal artery and veins. Three sutures were placed in the kidney capsule to control the bleeding that occurred at the biopsy site

A biopsy of a lymph node (called cranial mesenteric) located in the center of the abdomen was also obtained. This helps us determine if the cancer has spread.

This is what cancer looks like inside a kidney that has been cut open. The the left side of this open kidney the cancer goes from the 7 PM to 1 AM mark

cancerouskidney

Treatment

Acute Renal Failure

This form of renal disease needs immediate and aggressive treatment to prevent death. In some instances we will send you to a referral center that has dialysis equipment to filter the blood of waste products while your pet’s kidneys recupterate.

Cats that have a urinary obstruction need to be unblocked immediately. If not, excess potassium in the bloodstream (hyperkalemia) can cause death to to its affects on the heart.

Any drug suspected of causing the problem is stopped immediately, and underlying problems are addressed. Fluid therapy is critical, and consists of saline and dextrose solutions initially. Fluid therapy corrects fluid and electrolyte imbalances, increases the blood flow to the kidneys, and starts the process of diuresis.

Cats need to maintain their caloric input in order to minimize the metabolism of protein for their caloric needs. Metabolizing excess of amounts of protein will increase uremia, causing a further deterioration in condition.

Pets that are still not urinating after this initial fluid therapy are given Lasix or mannitol. Excess potassium (hyperkalemia) is a common finding in ARF. If mild, fluid therapy alone should correct the problem. If severe, regular insulin and sodium bicarbonate are used. Pets with ARF are sensitive to ulcers and infections, so treatment for these problems is sometimes initiated.Ethylene glycol (antifreeze) poisoning is an example of ARF.

Pets that have heart disease are sensitive to IV fluids because excess amounts can cause an overload to the lungs called pulmonary edema. These pets pose a dilemma. If we do not give them enough fluids the kidney problem will worsen. If we give enough fluids to help flush the waste products out of the bloodstream, these same fluids might cause pulmonary edema.

This radiograph is of the chest of a normal dog. The heart (H), windpipe (W), and lungs (L) are labeled. The lungs are black because they are filled with air. This is how normal lungs look on a radiograph.

This dog has pulmonary edema. The air filled lungs are no longer black, they are white from the fluid that has built up. This is a very serious condition.

Chronic Renal Failure

This is the version of kidney disease we encounter most often. The prognosis is guarded, and depends significantly on how long the disease process has been present along with your pet’s age. Pets (usually geriatric) that have other diseases  that are common at this age can make this difficult to treat if not caught early enough.

Many pets (especially cats) that are brought to our hospital have CRF that has progressed to the point where the problem has become similar to ARF. These pets need to be hospitalized and put on intravenous fluids almost continuously to get them over this acute phase. We will closely monitor their BUN and creatinine before therapy is instituted and during hospitalization, to ascertain if their kidneys are responding to fluid therapy. If the BUN and creatinine do not drop significantly after 24-48 hours of intravenous fluids then the prognosis for recovery is poor.

Many treatments have been advocated to help minimize the symptoms of CRF (also called the uremic syndrome). None of them can cure the problem, and not all of them have proven to work, so it is important that we tailor make each pet’s therapy to its individual needs. In addition, indiscriminate use of medication to treat a perceived problem can make the kidney disease worse. This applies to almost every drug, since the kidneys are so intimatley invovled in the metabolism of drugs. The medical axiom of “first do no harm” applies directy to kidney disease.

Medical management of CRF needs to address the following:

Protein and phosphorous regulation

XS protein in the urine

High blood pressure

Anemia

Dehydration and electrolyte imbalance

Low pH in the bloodstream

Stomach and intestinal ulcers

It is sometimes easy to forget some of the more common sense remedies that are available to treat diseases, especially true in kidney disease with all the web sites and advice from people who have encountered this common problem. Fresh water should be available at all times for your cat. You should fill the water bowl at least 3 times per day to help stimulate drinking. Undue stress should also be minimized at all times also.

Diet

Pets with CRF need to be fed a diet that has limited amount of high quality protein. Less protein in the diet leads to less work the kidneys have to perform by removing the nitrogenous waste products that are the end result of protein metabolism. Protein is vital to all bodily functions and can not be indiscriminately limited. As a matter of fact, if protein restriction is not implemented carefully it can make the uremic syndrome worse.

High quality protein means that it contains more essential amino acids, which are those the body cannot produce and must be obtained in the diet. The commercial food that we recommend for kidney disease is called K/D©. It is made by Hills© and is available only from a veterinarian because it is used to treat a specific disease. In addition to high quality protein it also has less phosphorous and sodium.

This food is the gold standard for CRF, and has been used successfully for decades to slow down the progression of CRF.

Most cats take readily to K/D, although it can sometimes be difficult to change the diet on an older cat. Many of the cats are eating poorly and have already lost weight due to the kidney disease, so we don’t want to add to their problem by feeding a diet they won’t eat. Mixing this new food in partially with the regular diet and heating it up a little (for the canned food) in the microwave helps. adding a small amount of a tasty fluid like clam juice can make it taste better.

It is better to have a cat eat anything than to have a cat that won’t eat anything, even if that diet is made to help the kidneys. Sometimes the best we ca hope for is to mix some K/D in with whatever food it ate prior to its diagnosis of CRF.

Water soluble vitamins (ex.- B-complex vitamins) are easily depleted in a pet that has PU/PD. Supplementation can be helpful.

Do not use foods that are lableled “for urinary health”. They are treating a different problem called FLUTD. These foods change the pH of the bloodstream in a way that is detrimental to the kidneys.

Since CKD is so prevalent in cats as they get older, it is a good idea to introduce K/D into the diet when your cat is 8 years of age, and transition it to K/D 100% by the time it is 10 year of age. This act alone will be a huge help to mitigate the progression of CKD.

Phosphorous lowering medication

Pets with CRF might have an increase in their phosphorous levels as the disease progresses. This excess phosphorous can add to the anemia that is common with CRF. It will also dramatically influence calcium metabolism in the body through a hormone called parathyroid hormone. The end result will be painful calcium deposits in the bones and internal organs, including the kidneys. This will also add to the scarring and add to the progression of CKD.

As already mentioned, K/D©is restricted in phosphorous, and should be used in combination with phosphorous binding medication. The phosphorus binding medication we use, which always needs to be given with food, is called Epakatin by Vetoquinol©.

Potassium increasing medication

Pets with CRF will have a decrease in their potassium levels as the disease progresses. This does not always show up on a blood panel. Using oral supplements and adding additional potassium to fluids helps counteract this problem. Oral potassium is called Renal K+©, and it comes in a paste for easier administration.

Urine protein reducing medication

Reducing protein in the urine is believed to help slow down the progression of the disease. ACE (Angiotensin Converting Enzyme) inhibitors (ex- Enalapril) or ARB’s (Angiotensin Receptor Blockers) are used when the urine protein:creatine ratio is greater than 0.5 in the dog and greater than 0.4 in the cat. These drugs are given for 30 days and then the urine is checked to see if there is either a 50% reduction from the original test, or if the ratio is below 0.5 in the dog and 0.4 in the cat.

Anemia fighting medication- Darbopentin

One of the long term affects of CRF is anemia due to a lack of erythropoietin secretion from the kidneys. This hormone can be supplemented to help minimize anemia.

Fluids

One of the most important treatments for CRF is the administration of supplemental fluids. Whenever we tell people their pet with kidney disease needs fluids they commonly respond “its OK, he/she already drinks a lot of water”. Unfortunately, this excess drinking of water is a result of kidney disease, and not a sign that the pet is drinking adequate amounts of water. Cats in particular are not good drinkers, and need additional water to what they are already drinking.

If your pet is hospitalized we will give them intravenously (IV) because of greater effectiveness and accuracy. If your pet responds to IV fluids during its hospitalization we will initiate the use of subcutaneous (SQ.) fluids at home on a daily basis.

This area of home treatment is so important that we have devoted a complete page to its use. Please click here to learn about the proper technique, then return to this section for more treatment options.

Most cats with CRF should receive between 50 ml and 100 ml of SQ fluids at least several times per week. As the problem progresses it will become necessary to give this fluid on a daily basis. We commonly add B-complex vitamins to the fluid bag since these water soluble vitamins are excreted the more we give supplemental fluids. Feeding a food designed for kidney disease like K/D will also help minimize the depletion of water soluble vitamins.

Blood pressure medications

Hypertension is a common occurrence as the disease progresses. Any systemic blood pressure of 160 mm or more should be treated. Blood pressure lowering medications like Norvasc (calcium channel blocker) and Enalapril (ACE ihnibitor) will help counteract this problem. All cats initially diagnosed with CRF should have a blood pressure taken. It should be rechecked at least every 6 months.

Some cats might respond to ACE inhibitors to decrease the protein in their urine. Further studies are needed in this area to determine efficacy.

Anti-ulcer medication

Some cats with CRF don’t eat well because of nausea due to excess hormone secretion in the stomach. Tagamet or famotidine is used to counteract this problem. If we suspect an ulcer in the stomach due to the toxins that have built up we will use Tagamet also.

Anti-vomiting medication

Vomiting is a common problem in pets with CRF. It occurs as a result of uremic toxin buildup in the bloodstream and alterations in hormones that regulate gastric secretions. Vomiting will cause dehydration, leading to a decreased flow of blood to the kidneys (decreased GFR) and an increase in azotemia. We use a drug called Reglan  or Cerenia to alleviate vomiting symptoms.

Antibiotics

Animals weakend by kidney disease are more susceptible to infection. These pets are commonly older and have significant dental disease. Antibiotics help them fight off infections. The antibiotic dose might have to be adjusted since many of them are removed from the body by the kidneys. Pets with CKD commonly have urinary tract infections due to bacteria, so a urine culture and sensitivity is needed in these pets to see if this problem is present.

Anti vomiting medication

Pets with CKD are commonly vomiting. This is a sign of how sick they are, and it also precludes them from getting proper nutrition, which is crucial in the treatment. Putting these pets on Cerenia, a very effective anti-vomiting medication, is necessary if your pet is vomiting. There is an injectible form of this drug used in an acute case, and an oral version for long term use.

Appetite stimulant medication

Pets with CKD do not eat well for many reasons. Getting them to eat is crucial, and some of them need appetite stimulants. The most effect ones we have found are Periactin and Mirtazapine.

Probiotics

 This supplement digests non-protein nitrogen in the intestines, mininizes BUN and creatinine levels, so there is less work for a diseased kidney.

Feeding Tubes

This overlooked and effective treatment helps dramatically for cats with CKD that are not eating well, are vomiting, and are difficult to medicate orally and with SQ fluids. We have a detailed page on feeding tubes.

Miscellaneous treatments

There are other supplements and medications used in CRF that might be of some benefit, although this is unproven. As long as they do not cause the problem to worsen they might be worth trying. Anabolic steroids– They are also used in older pets for arthritis and appetite stimulation with good success. They might help counteract the affects of anemia, although this can not be relied upon. DecaDurabolin  is the one we used most frequently. Drugs like this are no longer readily available. Calcitriol– It is postulated (there is no proof) that some of the symptoms of CRF are the result of elevated levels of parathyroid hormone. This hormone helps in the regulation of calcium levels in the bloodstream. By adding low doses of the hormone calcitrol the parathyroid hormone will be suppressed, and your pet might feel better. The phosphorous level must be controlled, and the calcium level monitored closely, if one of our doctors decides to use this modality.

Kidney Transplantation

At some select veterinary universities (University of Georgia) a new kidney can be transplanted into a cat. This does not cure the problem, it is a help in controlling the problem in cats that are losing weight and are anemic in spite of medical therapy. This specialized surgery can cost upwards of $10,000. Your cat has to be kept on immunosuppressive therapy (cyclosporine and prednisone) the rest of its life, and the donor cat has to be adopted. Complications can occur, especially rejection of the new kidney.

This is Skipper with his wonderful mom in for special testing before he goes to Georgia for his kidney transplant

Skipper2

Skipper returned several months later feeling much better and with his new brother!

Skipper1

Prognosis

Pets presented with renal disease, whether ARF or CRF, carry a guarded prognosis. It can be successfully controlled in most circumstances, especially if the diagnosis is made early enough. If your pet is hospitalized with CRF we will closely monitor its blood panel, paying special attention to BUN, creatinine, and phosphorous. If the excess levels of these tests decrease dramatically during hospitalization, and your pet improves clinically, then the use of K/D food, medications and SQ fluids at home are usually advantageous.

All pets that have been diagnosed with CRF should have a blood panel, a urinalysis, blood pressure check, and physical exam performed every 3-6 months. This disease will progress, and other diseases might present themselves, so this type of monitoring is crucial for a good quality of life.

For more information on this disease please visit the IRIS kidney page.

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Cognitive Dysfunction Syndrome (CDS)

Growing old is a natural process and a fact of life, for all of us, including our four-legged family members. This is especially prevalent in dogs since they age faster than us humanoids. Family members will probably be the first to notice the subtle changes of Cognitive Dysfunction Syndrome or CDS. It may be more than just “getting old.” Dogs with CDS may show signs of confusion, forgetfulness, less responsiveness, and/or other various behavioral changes that are not a normal part of aging. These subtle signs might not be exhibited in the examination room so we may not see them during an examination.


Cause

CDS is believed to be caused by physiological and chemical changes in the brain of aging dogs that affect brain function. These may include accumulation of B-amyloid, declining neurotransmitter activities, or increased activity of monoamine oxidase-B, an enzyme that may catalyze the metabolism of dopamine.1

In MRI (Magnetic Resonance Imaging) studies of the head, images show black and white cross-section “slices” of the brain. In MRI studies of older dogs with CDS, we see changes when compared to MRI studies of younger dogs. In the images above, note the ventricular space enlargement (V arrows) and hippocampus tissue shrinkage (H arrows) seen in the older dog image on the left, compared to the younger dog image on the right.1


Symptoms


Disorientation
(not due to vision or hearing loss)
Wanders aimlessly
Appears lost or confused in familiar surroundings such as the house or yard
Gets “stuck” in corners or under or behind furniture
Stares into space or at walls
Has difficulty finding the door
Stands at the wrong door to go outside
Stands at the “hinge” (wrong) side of the door
Does not recognize familiar people
Does not respond to verbal cues or their name
Appears to forget the reason for going outside
Activity and Sleep Sleeps more in a 24-hour day (overall)
Sleeps less during the night
Decrease in purposeful activity in a 24-hour day
Increase in aimless activity (such as wandering, and pacing) in a 24-hour day
Housetraining (for dogs previously housetrained) Has “accidents” (urinates or defecates) indoors
Has “accidents” indoors in view of family members
Has “accidents” indoors soon after being outside
Signals less to go outside (for dogs who previously signaled/asked to go outside)
Interaction with Family Members Solicits attention less
Less likely to stand/lie for petting (walks away)
Less enthusiasm upon greeting
No longer greets family members (once the dog has realized that family members have arrived)

Diagnosis

Since a biopsy of the brain is not usually a diagnostic option, a presumptive diagnosis can be made when there are clinical signs consistent with CDS and the absence of any underlying medical causes.

For a suspected case of CDS, as for any behavior problem, a history, physical examination, and diagnostic tests are needed to rule out the presence of any medical conditions that might affect behavior. These might include diseases of the internal organs, especially liver, kidney, and heart.

Additionally, primary and secondary behavioral problems need to be ruled out such as separation anxiety, noise phobias, or housesoiling.

Medical Conditions with Behavioral Components:

Medical condition Associated clinical signs

Sensory dysfunction

(loss of sight, hearing, smell)

Increased irritability, fear or aggression
Decreased appetite
Increased vocalization
Changes in sleep-wake cycle
Disorientation
Decrease in greeting behavior
Inattentive, decreased responsiveness to verbal commands

Urinary tract disease
Renal disease
Lower urinary tract infection

Incontinence, loss of housetraining
polyuria (urinating more)
polyphagia (eating more)
stranguria (painful urination, straining to urinate)
pollakiuria (urinating more frequently)

Osteoarthritis

Weakness, reduced mobility and activity
Increased pain, irritability
Possibly inappropriate elimination

Hypothyroidism

Decrease in activity
Increased irritability or aggression
Reduced tolerance to cold

Hyperadrenocorticism
Cushing’s disease

Polyphagia (eating more), polyuria (urinating more), restlessness
Decreased social interaction, responsiveness to commands and greeting behavior
Reduced activity
Loss of housetraining
Disrupted sleep-wake patterns

Neurological disorders

(primary or secondary
intracranial neoplasia)

Changes in sleep patterns, eating habits, housetraining, aggression, docility

To obtain a complete medical and behavioral history, we may ask many questions because signs of CDS may be subtle and not be exhibited in the examination room during during an examination. A printable Senior Dog Behavior History Form to aid in diagnosis of CDS is available by clicking here.

We will perform a thorough physical examination. In addition, a brief neurological examination will include assessment of cranial nerves, evaluation of postural reactions, especially conscious proprioception, and evaluation of the perineal reflex to assess sphincter function.

Typical diagnostic tests would include a serum chemistry profile, complete blood count (CBC), and urinalysis. Additional tests may be warranted based on the patient’s history and physical examination results.

Another method of diagnosis is response to therapy. If your dog improves when treated then there is a good chance he has this disease.


Treatment

Anipryl® is a medication, in tablet form, generally given once a day. We will recommend the appropriate dose for each individual patient. You can learn much more about it by clicking on the link.


Additional Reading:

1. Cognitive Dysfunction Syndrome and Other Geriatric Behavior Problems; CE Advisor a supplement to Veterinary Medicine, Feb 1999.[view PDF format].

2. Controlling CDS with Anipryl®: Post Approval Field Research Results from Private Hospitals in the US; Pfizer Animal Health Technical Bulletin, Dec 2000. [view PDF format]


You will need the Adobe Acrobat Reader to view and print the bulletins and forms, which are in PDF format. If you already have Acrobat® Reader, you can immediately download and print the documents. If you need a copy of the Adobe® Acrobat® Reader®, click the icon below to download it free of charge from Adobe®.


References:

  1. Adding New Science to the Practice of Medicine – Senior Dog Health, canine Cognitive Dysfunction Syndrome and anipryl® Senior Health Care advisor Program, Pfizer animal Health
  2. Campbell, S; Controlling CDS with anipryl®: Post approval Field Research Results from Private Hospitals in the US; Pfizer animal Health Technical Bulletin, Dec 2000.

Developed for Long Beach Animal Hospital, by Glenna M Gobar DVM, MPVM, MS, courtesy of Pfizer Animal Health; Sept 2001

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Demodectic Mange

Demodectic mange (Demodecosis) is caused by an external parasite that is also present in low numbers on healthy animals, including people. Whether or not a pet shows symptoms of this disease depends primarily on their immune status. Since there is no easy test to determine immune status, it is impossible to predict which pets will get this disease, or how well a pet will heal if it shows symptoms of demodex. It is important to note that the diagnosis of this skin condition, like most skin conditions, cannot be made just by looking at a pet. Diagnostic tests are mandatory to arrive at a correct diagnosis and achieve a satisfactory outcome to therapy. Stating that an animal looks “mangey” is not the same thing as making a positive diagnosis of mange. Pets that have Ringworm, allergies, Cushing’s or Sarcoptic mange can look like they have demodex.

Cause

Demodectic mange is caused by a mite, a microscopic ectoparasite that infects the hair follicles. Most pups pick up these mites from their mother when they are nursing, and do not normally cause any problems. It is those pets that have an inadequate immune system that develop this disease.

The parasite is cigar shaped and has several pairs of legs. It is only visible under a microscope. This is a picture of one that is laying on its back, its legs are towards the right, and its mouth is at the far right.

5075

There are underlying causes that can weaken the immune system and make a pet more susceptible to this disease. These include the chronic use of cortisone, Cushing’s disease, heartworm, cancer, and hypothyroidism.

Adult dogs that have demodex take longer to treat than young dogs.

Symptoms

One of the most common symptoms of this disease is small patches of hair loss (alopecia), towards the front of the body initially, with the ability to affect the whole body. When it is present in adult dogs it commonly affects the feet.

If a pet has only a few small patches of alopecia the disease is classified as localized. If it has spread throughout the body it is classified as generalized. Most pets that have demodectic mange are young, which is a big aid in the diagnostic process.

The patch of hair missing on this pups face is caused by Demodex, and is an example of the localized classification.

Face

This is an example of generalized demodecosis on the chest and front legs. This is a serious condition and carries a guarded prognosis.

Chest

Diagnosis

The primary way to diagnose demodectic mange is to do a skin scraping where the patches of alopecia occur. The fortunate thing about demodex is the ease of diagnosis in most dogs (Shar Pei’s can be an exception). In most cases the mites are easy to find under the microscope, and if your pet is diagnosed as having this disease, one of our staff members will show them to you under the microscope. A positive skin scraping of large numbers of demodex mites, along with alopecia (remember demodex is naturally found in the skin also), is verification of demodectic mange and necessitates treatment.

Treatment

We are fortunate to have several medications at our disposal to treat demodecosis. Unfortunately, one of the most common medications called Mitaban, is no longer available. These medications have proven to be highly effective, and have saved many pets from suffering, and even euthanasia. Sometimes the most we can hope for is to control the problem, not cure it. Treatment duration needs to based on skin scrapings, not just the appearance of the skin. A skin that looks like it is healed can still harbor demodex mites. This is especially true for adult dogs with feet lesions.

Unfortunately, due to the fact that the immune system is paramount in whether or not your pet gets this disease, no guarantee can be made that these medications will work. No matter which form of demodex is treated, several ancillary issues need to be addressed. Your pet needs to be on optimum nutrition, stay current on vaccines, and be free of internal parasites (worms). Like any disease process, the psychological needs of your pet need to be met, which includes plenty of exercise, TLC, and access to fresh water at all times. Other skin conditions like allergies can occur simultaneously, and need to be treated also.

  1. Localized Treatment

    Bathing with an antibacterial shampoo is the first step in therapy. This loosens up scales, removes oily discharges, and decreases the secondary bacterial infection that is usually present.

    Localized demodex was historically treated with a medication called Goodwinol. It is a creme that is rubbed into the areas of alopecia once daily. This rubbing initially causes more hair to fall out, but within 1-3 weeks the problem usually goes away. If more areas of alopecia appear during this time they should be treated with Goodwinol and brought to the attention of one of our doctors during recheck exams.

    Another treatment for localized demodex involves the use of Mitaban mixed into olive oil. This mixture is applied on the areas of hair loss daily. It is possible for localized demodex to progress to generalized demodex even if it is treated. Mitaban is no longer available.

    Localized demodex might even resolve without any treatment.

  2. Generalized Treatment

    Generalized demodex is treated with a combination of medications and modalities. It is important to understand that treatment may take 2-3 months to be effective. The hair is usually clipped to allow the topical medication easy access to the skin, which makes it substantially more effective. Secondary pyoderma (skin infection) is usually present also, so your pet is put on oral antibiotics for several weeks to months.

    The main drug used to treat generalized demodex in the past is called Mitaban. Unfortunately, Upjohn no longer makes it, so we have to use substitutes. Mitaban has to be used precisely by label instructions. Since it is difficult for people to do this properly in their homes, we treat most pets in our hospital. Pets are dipped once per week, in between these dips your pet should not be bathed. We continue dipping until successive skin scrapings are negative for the mites.

    Mitaban2860

    If Mitaban does not work there are other medications that are used with varying success to cure the problem. These include oral Ivermectin and Milbemycin (Interceptor). Side effects like excess salivation, incoordination, even coma and death are possible, so they must be used judisciously. They should not be given to Collies, Shelties, australian shepherds, or dogs that are positive for heartworm. There can be no guarantee that they will work, especially in a disease that is so closely associated with the immune system. Spaying infected females is helpful.

    Promeris, a flea and tick treatment is highly effective. Even though Pfizer no longer makes it our hospital has a supply of it.

    Advantage Mulit can also be used to treat generalized demodecosis.

Prevention

Pets that have this disease should not be bred. Otherwise, it is difficult to predict just what pets will get this problem.

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Diabetes Mellitus (Sugar Diabetes)

This page describing diabetes mellitus (DM) is very thorough and will require some study if you want to understand it fully. There is a different kind of diabetes, called diabetes insipidus, which is not the same disease. In general, when most people say a pet or a person has diabetes, or  if they also say sugar diabetes, they are refurring to diabetes mellitus.

Sugar diabetes, more correctly know as diabetes mellitus (DM), is a complex disease that is difficult to control, particularly in cats. Proper treatment requires a commitment on your part, usually for the life of your pet. It is well worth the effot in most cases because response to treatment is usually quite rewarding.

By definition, DM is a persistent hyperglycemia and glycosuria due to an absolute or relative insulin deficiency. By the time you are done with this page you will understand what all of this means.

You will also learn that some of the parameters of DM in animals are similar to humans, and many parameters are not, so be careful of extrapolating any experience you have between the two. DM can occur in many different species like birds and Guinea Pigs, although it is most commonly diagnosed in dogs, and especially cats.

Obesity is a big reason pets get DM. Fat is not just fat, it causes inflammation, leads to the rise of insulin resistance, which means your pet gets DM and does not respond well to insulin treatment. Most obese cats are prone to be what is called prediabetic. It all has to due with a hormone called amylin elevated in the bloodstream of overweight cats.

You can go far in preventing DM by keeping your pet at a normal weight, and feeding your cat a food that is higher in protein and lower in carbohydrates. Routine exams, that include blood panels and urinalyses that both monitor glucose, are important as your pet ages.

It will help if you learn these medical words because they will be used on this page:


Normal Physiology

The ability to use a food source for energy is critical to the success of any species, therefore nature has very sophisticated mechanisms to regulate this process. These mechanisms are extremely complex, and only those mechanisms that relate to diabetes mellitus will be summarized for the sake of simplicity.

In response to a decreasing blood glucose level the appetite center in the brain is stimulated and hunger ensues. A meal is then eaten, which consists of fats, carbohydrates, and proteins, in different percentages. When these fats, carbohydrates, and proteins are broken down by the digestive system and absorbed into the bloodstream, they are used by the body for various functions. The main function of the carbohydrates is eventual conversion to an energy source in the form of glucose, the primary energy source for all cells in the body. Some of this glucose is stored in the liver in the form of glycogen, which is released and converted back to glucose when cells need energy in-between meals.

Carbohydrates can be complex or simple. Complex ones are bread and pasta, simple ones are lactose (the carbohydrate in milk). When these carbohydrates are absorbed in the bloodstream through the intestines they are converted to glucose by the liver. The simple ones, like lactose, are rapidly converted and will immediately raise the blood glucose level. The more complex carbohydrates take longer to be metabolized to glucose by the liver, as a result they raise the blood glucose level more slowly. This point becomes important when treating both hyperglycemia and hypoglycemia.

Once in the bloodstream the glucose that circulates throughout the body is available for use by all cells as their primary energy source. These individual cells cannot absorb this glucose that passes by in the bloodstream unless the hormone insulin is circulating in the bloodstream at the same time. Insulin causes a chemical reaction in the cell wall that allows the glucose to enter the cell. The only cells in the body that do not need insulin to absorb glucose are specific brain cells.

Insulin originates in a group of cells called the islets of langerhams that are located in the pancreas. Insulin comes from the beta cells in the islets. It is secreted into the bloodstream in response to an increase in glucose in the bloodstream, a normal occurrence after a meal is eaten. The higher the glucose level the greater the amount of insulin secreted. Since the absorption of simple carbohydrates will cause a more rapid increase in blood glucose there will be a more rapid increase in insulin secreted. The complex carbohydrates will cause a more gradual rise in the insulin level.  This fact becomes important in feeding a diabetic patient.

The normal physiology is even more complex. Insulin also has a large effect on fat and protein metabolism. In addition, the pancreas also secretes a hormone called glucagon in response to a decreasing blood glucose level. Glucagon originates from the alpha cells in the islets, and its role is to help the liver convert glycogen back to glucose. As can be expected, glucagon will increase the blood glucose level, and counteracts the blood glucose lowering effects of insulin. Insulin and glucagon work in a negative feedback loop that allows for a very refined system to keep the blood glucose level at an optimal level for the energy requirements of each individual cell. The liver is a major part of this loop, acting as a blood glucose buffer to keep the blood glucose at optimum levels. This is a highly refined process that is fine tuned over thousands of years and works extremely well.

In general, brain cells do not need insulin to utilize glucose. A specific area of the brain, called the appetite center (in the hypothalamus), monitors the amount of glucose that circulates in the bloodstream. The lower the blood glucose level in the cells in the appetite center the greater the appetite. Unlike most of the brain cells, the ability of glucose to enter the cells of the appetite center is dependent upon insulin. In diabetes mellitus, with its lack of adequate insulin in the bloodstream, these appetite center cells don’t monitor glucose levels properly, thinking the blood glucose is low. As a result, the pet develops polyphagia to correct for this perceived problem. The additional food that is then eaten further increases the blood glucose level.

The pancreas does more than secrete insulin and glucagon into the bloodstream. It is the primary source of enzymes that are secreted into the small intestines (not bloodstream this time). These enzymes are secreted in response to the presence of food in the digestive tract, and are the primary way that many nutrients are broken down and absorbed by the intestines into the bloodstream. The way these energy sources are acted upon by the enzymes, and how they are eventually utilized by the liver, are also factors that effect the blood glucose level.

To further complicate the picture, epinephrine (adrenaline), cortisol (cortisone) and growth hormone also influence the blood glucose level.

This is a picture of the pancreas of a cat. It is adjacent to the beginning of the small intestine called the duodenum. The pancreas is the pinkish tissue directly under the cylindrical duodenum. For such a small organ it has an important job.

Now that you are an expert at normal physiology, lets learn what happens when the normal mechanisms described above go wrong. This is called pathophysiology. What causes this pathophysiology, leading to a lack of insulin production by the pancreas? It is multi-factorial, and includes:

  • Genetic predisposition
  • Infection
  • Toxins
  • Inflammation

Obesity and a lack of physical activity are predisposing factors, especially in cats.

Pathophysiology

The relative lack of insulin causes the blood glucose to go abnormally high. Normal blood glucose in a dog or cat varies from 80 to 150, but can temporarily go much higher (300-500 or more) in stressful situations. When the blood glucose is consistently high, as seen in diabetes mellitus, several negative effects occur.

Inadequate insulin levels force the cell to perform its functions with alternative sources of energy besides glucose. This causes problems for the organ that is made up of these cells, and eventually will lead to significant disease and the complications that occur in untreated diabetes mellitus.

The cells of the body (except most brain cells) are deprived of their primary source of energy. This means they do not function at optimum efficiency. Since they are starved of glucose they need to rely on other sources of energy, namely fat and amino acids. These are not as good an energy source as glucose in the long run.

To utilize amino acids as an energy source the body needs to break down protein. A large part of this conversion occurs in the protein in muscles cells. As this conversion from protein to amino acids progresses the body loses its muscle mass and weight loss occurs.

Metabolism of fat as an energy source is a normal response when cells do not receive adequate glucose for their energy. In the short term this process is highly advantageous. Fat has twice as much calories as proteins and carbohydrates, so it is a concentrated source of energy in the short run. If the fat metabolism process goes on for a prolonged period of time it becomes detrimental, and leads to the buildup of byproducts from fat metabolism. The main byproduct is a compound called ketones.

The ketones that build up in this process change the pH of the blood, further dehydrate a pet, interfere with other metabolic processes, and cause fatty infiltration of the liver. Ketones also cause vomiting, which leads to further inappetance and additional dehydration and electrolyte imbalance. Further inappetance causes the cells to use even more fat as an energy source, causing an uncontrollable spiral, and sometimes even death. Any diabetic pet presented with ketones in its urine is a medical emergency. These pets have what are termed diabetic ketoacidosis, abbreviated as DKA.

In addition to the liver, the kidneys are another important organ in this disease. The primary role of the kidneys is to filter the blood. As the blood passes through the kidney filters essential nutrients are returned to the bloodstream and waste products are excreted through the urinary system. Glucose is one of the many molecules that is returned to the bloodstream after it has passed through the kidney filters. Once the glucose exceeds 200 mg per deciliter (this varies by species, cats tend to be higher) in the bloodstream though, the kidneys can no longer selectively return all of this glucose back into the bloodstream. This is called “exceeding the renal threshold”, and is a very important part of diabetes mellitus.

As a result, glucose spills into the urinary tract and bladder in excessive quantities. Since glucose attracts water (called the osmotic effect) it pulls fluid out of the pet and causes polyuria. To compensate for this excess urination the pet drinks more water, and now has polydypsia. It now has the symptoms we abbreviate as PU/PD. Eventually it causes dehydration when the pet can’t drink enough water to keep up with the increased urination. In addition, the excess urination pulls important electrolytes out of the bloodstream like sodium and potassium, which leads to lethargy and weakness. The loss of glucose also depletes the body of its primary energy source, so additional weight loss occurs. To further add to a diabetic pet’s woes, the excess glucose that builds up in the bladder feeds bacteria that can cause a urinary tract infection.

Why the pancreas stops secreting adequate levels of insulin is a mystery. There is a strong correlation for diabetes mellitus to occur in cats that previously had an episode of pancreatitis. This makes sense because the pancreas is the source of insulin. Yet, many cats that have diabetes mellitus had no apparent pancreatitis in the past. In some pets the immune system attacks the beta cells in the islets and deposits a compound called amyloid which, makes the beta cells unable to secrete insulin. This amyloid, which contains a protein called amylin, is thought to play a significant role in non-insulin dependent diabetes (your will learn about this soon) because amylin is toxic to the cells in the islets of langerhams.

Another factor involved in non-insulin dependent diabetes is peripheral insulin resistance. This resistance plays a significant role in obese pets, which is a major predisposing role in the development of insulin. Genetics is also involved-genetics cannot be controlled, but obesity can.

Elevated levels of thyroxine, which occurs in feline hyperthyroidism, can also be a factor in insulin resistance.

So what does all of this mean? To summarize all of this pathophysiology:

    • Peripheral insulin resistance, due to obesity and/or the protein amylin found in amyloid, causes chronic stimulation of insulin production in the pancreatic beta cells.
    • Impaired insulin secretion causes insulin and amylin to accumulate in beta cells in the pancreas.
    • The high levels of amylin in the beta cells allows amyloid to deposit, further disrupting the ability of these cells to produce and regulate insulin. As the problem progresses non-insulin dependent diabetes eventually progresses, and at some point in time, the symptoms of diabetes mellitus appear.
      The pancreas can get a tumor called an insulinoma. In this case the pancreas secretes too much insulin and the blood glucose hovers at dangerously low levels. This problem is rare in most animals except for the ferret

Classification

Most people are familiar with the classification scheme used in human medicine. Even though the disease is similar in people and pets, the human classification scheme does not always correlate with diabetes mellitus in cats. Differentiating between Type I and Type II in cats can be difficult.

  • Type I

    Has similarities to insulin dependent or juvenile onset diabetes mellitus. Most commonly occurs in middle aged cats. Insulin is needed to treat the problem. This is also known as insulin dependent diabetes mellitus (IDDM).

  • Type II

    Similar to adult onset or non-insulin dependent in humans. Obesity is a significant risk factor. Insulin is not needed in all cases. Type II cats can become Type I cats when exposed to significant stress. Fortunately, when the stress is resolved they can revert back to Type II. This is also known as non-insulin dependent diabetes mellitus (NIDDM).

    Diabetes can occur secondary to other problems. Some of these problems include hormone imbalances and reactions to medications. A medication called Ovaban, a hormone used to treat numerous cat ailments, can cause diabetes if used excessively.

Symptoms

The classic signs of a cat or dog with diabetes mellitus are PU/PD. These signs of excess drinking and urinating are subtle at the beginning stages of the disease and are easily missed. This is especially true in outdoor cats who do most of their urinating outside, and dogs that urinate outside also.

Other symptoms include weakness, an increase in appetite, occasionally a decrease in appetite, weight loss, lethargy, and rarely, vision problems due to cataracts (this problem is more common in dogs). Cats with a severe liver problem associated with this disease might have icterus (jaundice).

An affected cat might even walk abnormally on the rear legs (called plantigrade posture) due to nerve problems as a consequence of the elevated blood glucose level. It is also known as diabetic neuropathy, and tends to occur as the disease progresses. The best way to prevent it is to keep the blood glucose level as close to normal as possible.

This is what the abnormal (plantigrade) posture looks like

These are also the symptoms of other diseases commonly seen in dogs and cats, and can only be differentiated by diagnostic tests. These other diseases include, but are not limited to, hyperthyroidismkidney diseasecancerliver diseaseCushing’s disease and adverse reaction to medications.

The yellow discoloration to these gums is icterus (jaundice). It is commonly, but not always, caused by liver disease.

Symptoms in dogs typically include:

  • PU/PD
  • lethargy
  • poor appetite
  • vomiting
  • weight loss
  • diarrhea
  • cataract formation

Just like in cats, many dogs with diabetes mellitus were overweight at some time in the recent past.

Dogs with diabetes commonly have other diseases concurrently. They include:

Diagnosis

By the time a diagnosis of diabetes mellitus is made the disease process has usually been present for a significant period of time. When the disease process first started there were no obvious symptoms because of compensatory mechanisms in the body. As diabetes progresses these compensatory mechanisms lose their ability to maintain euglycemia. Eventually, symptoms of PU/PD and weight loss occur and your pet is brought in to be examined. This emphasizes the point that middle aged and older pets should have a routine blood panel and urinalysis every year once they reach 8.

This is a complex disease, and no specific set of symptoms tells us your pet has diabetes mellitus. It is important to follow the tenets of the diagnostic process closely when making a diagnosis of diabetes mellitus, especially since kidney disease and hyperthyroidism have similar symptoms. We will use the diagnostic process as an example of how we make this diagnosis:

Signalment

Typically this disease is seen in obese cats that are middle aged or older, and more commonly in males (the opposite of dogs). Orange cats seem to get DM more often than other colors, but that could be because more of them are male. There is no specific breed predilection in cats.

Dogs are typically middle aged and older, with purebred dogs showing a higher incidence. Common breeds are:

History

The classic signs of PU/PD, polyphagia, and weight loss occur in many cases, but not all. These signs depend on how well entrenched the disease process is before your pet is brought in for an examination. Sometimes the only thing an owner notices are accidents around the house in a previously housebroken cat.

A consistent finding is obesity in the recent past. This predisposes them to DM, and we sometimes call them pre-diabetic if obese enough. These obese cats need to be closely monitored for DM with fasting blood glucose tests, urinalysis, and fructosamine tests. You will learn about these tests in or diagnosis section.

Since this disease occurs in middle aged and older pets there can be other diseases occurring simultaneously. Some cats have a history of vomiting in the recent past, an indication that they might have had an episode of IBD (Inflammatory Bowel Disease) or pancreatitis. Some cats are borderline diabetics that have had a recent illness, stress, or adverse reaction to medication. There might also be blood in the urine or straining to urinate, an indication of a urinary tract infection.

Cats presented in DKA might have a history of abdominal pain and distention, vomiting, inappetance, and lethargy.

Physical Examination

The findings of the physical exam depend on how severe the diabetes is, how long it has been present, what caused it, and if there are any other disease processes occurring simultaneously.

Many cats will have lost weight, yet they still could be obese. There might be dehydration, weakness, lethargy, an enlarged liver on abdominal palpation, and an acetone (juicy fruit) smell to the breath. Hypothermia and shock could be present in advanced cases and those with DKA.

Diagnostic Tests

The primary method of diagnosis is with a fasting blood panel and a urinalysis. The blood panel will reveal hyperglycemia (at least > 200 mg/dl) while the urine sample will reveal glycosuria. Not every case of hyperglycemia means a cat has diabetes mellitus. Cats that recently ate, or those that eat canned foods that are rich in sugar, might have blood glucose levels higher than the normal range. Cats that are stressed from a car ride, on cortisone, are in heat, on phenobarbital medication or hormone medications, might also have hyperglycemia.

Cats are unique in that their stress response can cause a tremendous rise (up to 4x normal) in the blood glucose. This is a common occurrence when we take a blood sample in a cat, and needs to be taken into consideration when we analyze a blood report. This stress induced response is a normal reaction to the release of epinephrine (adrenaline). It is a transitory response and will not persist like the hyperglycemia of diabetes mellitus. These cats sometimes need to adjust to a hospital environment before we are able to determine their true blood glucose level. It is always advised to check the blood sugar in dogs and cats after an 8-12 hour fast to give an accurate representation of the blood glucose level.

Here is a blood glucose report from our lab for a cat that does not have diabetes mellitus. The blood glucose is 317.

This cat has diabetes mellitus, its blood glucose is 390

How do we differentiate them when both are well above the normal range?

Diabetes mellitus is diagnosed when there is a persistent fasting hyperglycemia along with glycosuria, that is consistent with a history of PU/PD and polyphagia.

Other blood tests are sometimes used in this disease. The two more common ones are serum fructosamine and glycosylated hemoglobin. They are used to to distinguish stress induced hyperglycemia from diabetes mellitus, and to also monitor insulin therapy. They give us an indication of what the blood glucose level has been for the preceding weeks.

Fructosamine is formed when glucose reacts with amino acids that make up serum proteins like albumin, which is made by the liver. When the blood glucose is high, fructosamine also increases. Increased levels of fructosamine help confirm a diagnosis of diabetes mellitus, give us an idea of the presence of a persistent hyperglycemia, and help us monitor response to treatment.

Glycated hemoglobin (HbA1c), a tool to diagnose, monitor, and treat diabetes mellitus in people, is just start to get clinical application to dogs and cats with DM. This hemoglobin A1c test gives us a greater timespan to monitor glucose levels, up to 70 days in cats and 110 days in dogs, as opposed to fructosamine which monitors glucose levels for several weeks.  The A1c test is is not affected by daily blood glucose fluctuations, exercise, diet, or the amount of insulin in the bloodstream. As this test is tested for consistency and become standardized and cost effective we will implement its use as another aid to monitor and treat or diabetic patients.

In addition to glucose in the urine and ketones, the urinalysis might indicate that a urinary tract infection is present. This is detected by a change in the pH of the urine, excess white or red blood cells, and bacteria. Even if these are not present a urinary tract infection can still be present. This is why we recommend a urine culture and sensitivity looking for bacteria.

This is a urinalysis from a cat that has diabetes mellitus. Its glucose is 4+. Fortunately, it is negative for ketones, there are no white or red blood cells present, and there are no bacteria visible either.

This cat does not have ketonuria or an infection.

Treatment

The goal of treatment is to resolve the symptoms of poor appetite, lethargy, and PU/PD without inducing hypoglycemia. Dogs tend to be easier to regulate than cats, although preventing cataracts from forming is difficult in the dog.

Some cases of diabetes mellitus in cats are not straightforward. An obese cat can have NIDDM in its normal, unstressed home environment. These cats are secreting insulin but in low levels. As long as they are in a stress-free environment they are able to maintain euglycemia. If they encounter a stressful situation, get sick, or are put on certain medications, their blood glucose will increase. If it goes beyond the renal threshold for glucose, PU/PD will ensue.

These cats are then brought to a veterinarian because of the PU/PD and diagnosed as having diabetes mellitus. They are put on insulin therapy and the problem improves. The problem occurs when these cats are returned to their normal environment and the problem that started the increased blood glucose in the first place (stress, illness, drugs) is now gone. In some of these cases these cats will now become hypoglycemic because they are being given insulin injections when they do not need them. Identifying these cats that have converted from insulin-requiring to non-insuin requiring NIDDM is difficult. This is one of the numerous reasons why diabetic cats should be brought to our hospital every 1- 3 months for a urinalysis and blood glucose curve.

If we start a cat on insulin injections, it’s weight is or becomes normal, and it responds well to insulin injections (especially glargine), we might have a cat in remission, which is our ultimate goal.  In these cases we start lowering the insulin dose slowly, over several weeks to see if it still maintains a normal blood glucose.

Hypoglycemia, blood sugar that is too low, is your primary emergency problem. Symptoms to watch for include:

  • Walking abnormally, like your pet is drunk
  • Running into walls or circling
  • Staring into space
  • Shaking

All diabetic animals, especially cats, need to be closely monitored because urine and blood glucose levels are in a constant state of flux. Because of this you need to be in touch with your pet’s habits and observant of any changes. You also need to have Karo syrup available at all times for dogs and cats in case their blood sugar becomes low and they have problems. If you have no Karo syrup make up some sugar water and rub it on the gums.

Diet

Recent evidence suggests that feeding a high protein diet will help cats with diabetes mellitus.  This higher protein diet mimics what a cat’s physiology has been used to for millenniums. It leads to less release of hormones that affect blood glucose levels. Some cats on high protein diets will need little if any insulin injections. Some cats that are on insulin injections to control their diabetes can actually go off insulin when put on a higher protein diet. The food we recommend is Hill’s M/D.

Dietary therapy might be all that is needed for the obese cat with NIDDM. A cat that is underweight from diabetes mellitus should not be put on a high fiber diet. Since this disease is prevalent in older cats this change in diet might be met with resistance. In these cases mix the higher fiber food with its regular diet to get some advantage of the higher diet. Do not feed foods that contain excess sugar like semi-moist canned foods.

Dogs tend to do well with Hills W/D. The most important thing to remember is consistency. Your dog and cat should be fed the food they like to eat, in the same amount, at the same time every day.

Oral Hypoglycemics

The goal of oral hypoglycemic medication is to minimize glucose absorption by the intestines and to also minimize the conversion of glycogen to glucose by the liver. They also help increase insulin secretion from the pancreas. Oral hypoglycemics need to be used early in the disease before the beta cells are exhausted. Since so many pets are brought to us well past that stage, they do not work as well as in humans.

They are used in cats that are not underweight, have negligible ketones in the urine, no indication of pancreatitis or no history of being on medication that could cause hyperglycemia. In conjunction with diet, oral hypoglycemics can sometimes help us differentiate NIDDM form IDDM. Cats with NIDDM will have significantly lower blood glucose levels when checked several days after initiating this protocol.

Some cats will vomit and might even develop hepatitis from oral hypoglycemics. Giving the medication with food helps minimize vomiting.

The main one used is Glipizide. Due to variable response and potential side effects it is not used often.

Insulin

The thought of giving injections to your pet, especially a cat, can cause panic in some people. Keep in mind it is easier to give insulin injections with the tiny needle that is used, than it is to give a cat a pill. Once we show you how easy it is you will become an expert in no time. If you make it a positive endeavor, feeding around the same time, then a small treat, or a brushing or petting session just after the injection, it will be a positive experience for both of you.

There are many types  of insulin that have been traditionally used to treat IDDM in our hospital over the decades. Unfortunately, the manufacture, Eli Lilly, has discontinued the production of many of its insulin products.


Regular

FastActing- Peaks in 2-4 hours Lasts 5-8 hours


NPH

IntermediateActing- Peaks in 8-12 hours Lasts 18-26 hours


Ultralente

ProlongedActing- Peaks in 16-24 hours Lasts 24-36 hours


This chart gives you a relative idea of their peaks and duration of action. It is important to remember that every dog and cat will react differently and will not necessarily have this same graph.

Regular insulin is used initially to treat a cat or dog if it has DKA. Once the ketoacidotic state has been reduced we use the intermediate or prolonged lasting insulin. Your veterinarian will let you know which one might be most appropriate in your situation. Sometimes we need to try more than one type of insulin. What is just as important as the type of insulin used is the familiarity a doctor has with a specific protocol.

Most pets will need insulin given every 12 hours. This should coincide with a meal. You should decide ahead of time what insulin and feeding schedule works for you and your lifestyle because consistency is of utmost importance. The same thing goes for exercise since this affects insulin. Take your dog for the same type of walk at around the same time every day when possible to increase your chance of a good response to insulin injections.

For many years the insulin used to treat cats was derived from a beef-pork combination (90% beef and 10% pork) that was used in human diabetes mellitus. The pharmaceutical companies are now relying more on human recombinant (genetically engineered) insulin.

The goal of insulin therapy is to mimic naturally secreted insulin from the pancreas as closely as possible. This can be quite difficult in any species, let alone the cat. The dose of insulin and the type of insulin that is effective will vary from cat to cat and dog to dog. Once a proper dose is initially determined at some point in time in the future this dose will probably change.

Initially, insulin is dosed conservatively in order to see an individual dog and cat’s response and to minimize any chance of hypoglycemia. After your pet has been on this initial low dose we like to do a blood glucose curve to assess where we are, then make adjustments in dose accordingly.

There are many different types of insulin used. We will go over the ones most commonly used:

  • Glargine and Detemir- Ultra long acting

    Glargine, a human insulin has been successfully used in many cats. If used early in the course of the disease it is even possible to get a remission of the disease.  Those cats that do go into remission need to be monitored and kept at an ideal body weight or they might have a recurrence of diabetes mellitus.

    Glargine is more expensive than the other insulin’s used. This added expense might be worth it if your cats diabetes problem is actually cured of the problem. One of our doctors will discuss this with you and see if it is appropriate in your situation.

    Glargine has been show to be effective in some cats, although its long term efficacy has not been proven yet in a large number of cats. The same holds true for Detemir. More studies with a large number of diabetic cats over a long period of time are needed.

  • PZI (Protamine Zinc Insulin)- Long acting

    This is one of the more commonly used insulins in cats. It is usually given every 12 hours. We start with a dose of 1-3 units, and adjust as needed.

  • Vetsulin (Lente)- Intermediate acting

    This insulin is approved for use in dogs and cats, and is one of the more common ones used, especially in dogs. Its use in cats is increasing due to good results. It is made from purified porcine insulin which has the same amino acids as canine insulin. Because of this there should be more effective regulation of blood glucose with less risk of anti-insulin antibodies. It is an intermediate acting insulin, and in some dogs once daily dosing is adequate. Cats usually need to be given their injections twice each day.

  • NPH (Neutral Protamine Hadedorn)- Intermediate acting

    This has been the mainstay for treating diabetic dogs over many decades. It is still used, although we have been using Vetsulin much more frequently. It is not used in cats.

Ketoacidotic Diabetes Mellitus

Pets presented with DKA need immediate medical attention. They need regular insulin due to its ability to rapidly lower the blood glucose level. They also need fluids and electrolytes to correct dehydration, electrolyte imbalance, and acidosis (a change in the pH of the bloodstream). If this therapy is initiated too aggressively it might cause more harm than good. Our goal is to return your cat to a relatively stable state within the first 1-2 days after initiating this therapy.

Regulation

Diabetic pets need to be slowly  regulated (the correct dose of insulin needed). Many pets will take 4-8 weeks to find the proper level of insulin Most cats have well entrenched pathology that is not conducive to rapid change. The dose has to be given in small amounts initially to prevent hypoglycemia. It takes several days for a cat to respond to a change in dose. This initial regulation only gives us a starting point for your pet’s insulin dose since there will be numerous mitigating factors that will affect insulin levels when your cat returns home.

Initially we will use a low dose and have you administer the insulin at home at this dose for the next 7 days. After 7 days we will perform a glucose curve in our hospital over 10 hours.  The blood glucose curve will give us an idea of how it is reacting to the type and amount of insulin we are using. Every pet is different, so this trending is needed to understand specifically how your pet will react. This curve will give us an accurate picture of just how high and how low the blood glucose is. This will then allow us to further refine the dose of insulin. We will do this glucose curve every 7 days, refining the dose each time, until we have achieved are desired level.

Any other problem your pet has, especially UTI’s (urinary tract infections) needs to be corrected for insulin injections to lower the blood glucose properly.

Our goal is to get the blood sugar level down to somewhere between 100-250 mg/dl. Some pets are regulated fine even if the blood glucose peaks at greater than 250 mg/dl. It is much better to have a pet that has a slightly high blood glucose level than to try and refine the dose so closely that hypoglycemia is risked.

To monitor your pets blood glucose we take frequent samples. To prevent the constant irritation from obtaining this blood sample we put a catheter into one of your cat’s veins. This eliminates discomfort and also minimizes the stress response.

This cat has jugular catheter — to learn more about catheters click here

 

The first step in the process of running a blood glucose test in our hospital involves taking blood from your pet and putting it on a special strip.

This cat’s blood glucose reading is 63 mg/dl. It is hypoglycemic at this point.

The typical pet eventually needs anywhere from 2-10 units given from once to twice daily. Of course this dose depends on the weight of your pet, the type of insulin used, its diet, its exercise level, and its individual response.

Even though these blood glucose checks are critical, your input as to how well your pet is eating, acting, and how much it is drinking and urinating, are just as important. If your pet is doing well in all these parameters then the blood glucose is being regulated.

Insulin Injections

It is imperative that you administer the precise amount of insulin required since small changes can have dramatic effects. Be consistent and give the insulin the same time and at the same location every day. If your pet is on twice daily insulin injections give each morning and evening dose at the same time every day. Always feed your pet in the morning prior to giving the insulin. If it does not eat its food skip the morning dose of insulin. If it eats only half of its food, give it only half of its insulin dose. Giving a normal dose of insulin to a pet that is not eating greatly increases the risk of hypoglycemia. You must always err on the side of hyperglycemia instead of hypoglycemia.

Most cats eat small bites of their food throughout the day. This might or might not work in a diabetic cat because of the manner in which the insulin that is administered peaks. If it does not work, feed your cat twice each day, feeding part of its daily meal when you give the insulin in the morning. Make sure it has access to this same food when the insulin level is peaking later in the day.

A record should be kept of your pet’s food intake to note any changes. The same thing holds for its water consumption. Marking this on a calendar weekly will give you important trends and give you a good idea if you are on the proper dose of insulin.

The actual administration of insulin is very straightforward. As a matter of fact, it is easier to give insulin injections at home than it is to give SQ (subcutaneous) fluids to cats that have chronic renal failure, a common feline problem. This is because an insulin injection takes 1 second to give, whereas fluids take 5-10 minutes. The technique used to give insulin injections or SQ fluids is the same- click here to view an actual demonstration of the administration of SQ fluids. When you are finished learning the proper technique return here to finish.

You will never be forced into doing something that makes you feel uncomfortable. While your cat is in the hospital with us you can observe how we give the insulin injections. One of our nurses will demonstrate its proper administration when we release your pet from the hospital. You can return to our hospital for assistance in giving the insulin at any time.

In order to simplify the process we will give you an insulin syringe that has been designed to be used with the specific type of insulin your pet requires. You will be giving insulin in a measurement called “units”, and not in ml (milliliters) or cc (cubic centimeters) as is commonly used in most syringes.

 

The use of injections is very simple. If we are using U-40 insulin, then we use a U-40 syringe. If we prescribe 2 units of insulin, draw up the insulin to the 2 mark on the syringe and give the injection. That’s all there is- no calculations are needed on your part.

Some cats require such a low dose of insulin that we have to dilute it for proper administration. A special diluent is needed for this, and diluted insulin should not be used longer than 2 months. A special syringe is sometimes used for dilute insulin.

This is what a U-100 syringe looks like. The needle is very small and sharp so your pet will not feel it during its injection.

Insulin should be kept refrigerated at all times to preserve its freshness. When you purchase it at the pharmacy bring an ice pack with you. Prior to use it should be gently warmed in your hands.  Storing the insulin bottle on its side in the refrigerator will help in mixing.

Gently roll it (never shake it vigorously because excess bubbles will form) between your hands for 1-2 minutes to bring it to the proper temperature for administration.

Make sure you are in a relatively calm location when you give the injection. Hold the insulin bottle upside down and draw out slightly more than the number of units your cat requires. Tap the syringe a few times to remove any air bubbles-this aids in accuracy (a few tiny bubbles are OK). Push the plunger in the syringe slightly forward until you have the exact number of units you need to administer is in the syringe. Put the cap back on the syringe and put the insulin bottle back in the refrigerator. Do not reuse the syringe.

We will show you exactly how to do this in person, and give the first few injections for you until you get your confidence. In this picture you can see we have drawn 6 units into the syringe.

Give the injection in the scruff of the neck just as you would when giving SQ fluids described above. Your pet should not feel anything because the needle is so tiny and sharp. The whole process, from warming the insulin to giving the injections, should only take a couple of minutes. As you get confidence it is recommended to rotate your injection sites. We can shave a section of hair to make this whole process easier.

Improper administration of insulin is one of the most common causes for improper regulation. Please do not hesitate to contact us at any time for assistance in this vital procedure. Unless unavailable, only one person per household should be delegated to giving insulin.

Home Monitoring

The best way to monitor your pets blood glucose at home is to perform the blood glucose yourself. Ears and pads are areas in which a small prick will give sufficient amount of blood to run an in home blood glucose. In some cats this method of obtaining a blood glucose level is preferable to running a glucose curve in the hospital. This is because the stress of the car ride and the obtaining of blood several times while in the hospital can mislead us as to your cats actual blood glucose level.

Some of our clients use a home glucose kit to check their cats. It is easy to do once we show you, and gives a more accurate assessment of blood glucose levels at home than does the glucose in the urine. You only need a few drops of blood for the glucometer.

To use the glucometer you need to find an ear vein. You can see this one running horizontally under our nurses finger.

It is very simple to prick the ear with this machine and get your sample

 After you place a drop of the blood in the green tip the machine will give you a blood glucose reading in a few seconds

Most people prefer to monitor the glucose in their pet’s urine because it is simpler. Monitoring of the glucose in your pets urine will give you at best a rough idea of its blood glucose level. There are significant limitations to home monitoring using urine glucose as a criteria. We do not recommend it.

Urine glucose measurements do not necessarily correlate with blood glucose measurements, the more important of the two. Also, if the blood glucose level is below the renal threshold a negative glucose in the urine cannot differentiate between euglycemia and hypoglycemia. If you note a significant amount of glycosuria consistently for several days your pet needs a blood glucose curve.

One of the ways the urine dipstick can be particularly helpful is in monitoring ketones. Occasional trace ketones is no cause for alarm. Consistent ketonuria in a cat that is not feeling well requires immediate veterinary care.

To help in the urine monitoring process your cat’s normal litter can be replaced with special litter that will not absorb urine. You can also use regular paper, newspaper, or even plastic wrap in the bottom of the cage. There is even a special litter that reacts with the glucose in the urine.

One of the more common urine dipstick kits is the Keto-Diastix. In addition to monitoring glucose it also monitors for ketones.

This is the chart on the Keto-Diastix bottle. The box to the far left is negative, which is the goal. The next box to the right is 100 mg/dl. Its OK to have this urine glucose value on occasion.

On the same bottle there is a chart to monitor for ketones in the urine. Your goal is to have negative with an occasional trace.

What is just as important as urine glucose is your subjective interpretation of how your pet is doing. If the original symptoms are greatly reduced then you are probably giving an accurate dose.

Determining the daily dose of insulin required at home is not an easy task. We have learned over the years that blood glucose determinations are variable, and that in many cases it is your perception at how well you pet is eating, how active it is, and how its drinking and urinating has decreased that is more important.

A more accurate blood test is the fructosamine level, which gives us an average of your pets blood glucose levels of the last 2-3 weeks, and is much less variable than individual blood glucose determinations. The fructosamine test is obtained at our hospital, and should be performed every 3 months after initial regulation.

Do not make any changes in insulin dose unless you talk with one of our doctors. Do not make daily changes in insulin doses either, wait 3 days to determine if the new dose is having any effect.

Warning signs that necessitate an exam and blood glucose curve in the hospital:

  • Lethargy or significant increase or decrease in appetite
  • Significant increase in drinking or urinating
  • (100 mg/dl) or more glycosuria for > 2 days
  • Significant ketones in urine for > 2 days

Long Term Care

It must be understood that in most cases insulin administration does not cure diabetes mellitus, it only controls it.  As you learned above in the physiology section, the body has very sophisticated and refined mechanisms to keep the blood glucose at optimum levels. This can not be replicated easily by giving insulin. The exception to this is the occasional cat diagnosed early in the disease process and is not overweight.  Glargine seems to be the best insulin to increase the chance of remission .

To minimize problems we should monitor your pets’s blood glucose level in the hospital and perform a urinalysis every 3 months. Since cats can exhibit an exaggerated stress response causing a profound hyperglycemia, a glucose curve is necessary to ensure accuracy. Every 6 months we should also perform a complete blood panel to look for changes in other organs caused by the diabetes. A urinalysis at the same time is needed to monitor for a UTI (urinary tract infection).

A further reason to run a complete blood panel every 6 months is to monitor routine age related changes like hyperthyroidism and kidney disease. Diabetes can also predispose your pet to high blood pressure (hypertension).

This long term monitoring is important for another reason. In almost every diabetic pet insulin requirements change, necessitating the need for close monitoring and communication with us. If your pet goes into heat (another reason to spay females and even neuter males) its insulin requirements might change. In some diabetic cats the problem goes away and they no longer have a need for insulin. Giving insulin to these cats can cause hypoglycemia, which if it is severe enough, can lead to seizures.

Complications of Diabetes

  • Hypoglycemia

    One of the more alarming, yet relatively rare side effects to insulin administration, is hypoglycemia. You should be ever vigilant about its appearance and always be ready to treat it at home. Close observation of your pets appetite will go a long way towards preventing this problem.

    Symptoms include shaking, a starry eyed appearance, lethargy, shaking, greatly enlarged pupils, muscle tremors and even seizures. If the problem is serious and persists long enough, coma and even death can occur from depression of the respiratory system. Some pets don’t show any obvious symptoms except subtle behavior changes like sleeping more than usual. Since cats sleep most of the time anyway this can easily be missed.

    In most cases the cause is an overdose of insulin. A common scenario involves a pet that eats significantly less than its normal amount for the day. Hypoglycemia can result if the dose of insulin is not adjusted to take this into account. If your pet is not eating well and you are unsure of its appetite, either give less insulin that day or do not give any at all. A blood glucose test in the hospital will let us know for sure.

    Other causes of hypoglycemia include improper insulin administration resulting in an accidental overdose, along with cats that spontaneously recover from their diabetes and no longer need insulin. This is why close monitoring of the blood sugar level is important, either at home or at our office.

    If the symptoms of hypoglycemia are mild, feed your pet some of its normal food. For many pets this will suffice. If the problem is severe use Karo syrup, a simple carbohydrate. It is readily available at the supermarket and should be kept on hand at all times. Give it in small amounts or rub it on the gums. Pancake syrup, honey, sugar water or any fluid that has high amounts of sugar can be used also. These high carbohydrate remedies only last a short time so you might have to keep on repeating one of them. Also, it is a good idea to have a source of simple carbohydrates in your car or other important locations when traveling or even just going for a walk. It pays to be prepared.

    In the rare case that your pet has a seizure or seems comatose from hypoglycemia, it is imperative that you do not put anything into its mouth, including your fingers.  These pets need to be seen by a veterinarian immediately.

  • Liver Disease

    Cats with diabetes are forced into using an energy source that will eventually cause a fatty infiltration of liver cells. As a result the liver will not function at optimum capacity, a potentially serious problem since the liver is such a vital organ. The liver enzyme test on the blood panel will alert us to this complication. When the diabetes is treated this problem might resolve. Radiography might reveal an enlarged liver (hepatomegaly) due to the fatty infiltration.

    This liver is larger than normal-it is extending towards the right far beyond the margin of the ribs. The 4 white arrows on the bottom outline the lower edge of the wedge shaped and enlarged liver.

    One of the most important disease syndromes associated with a fatty liver is called hepatic lipidosis. It occurs in overweight cats that are exposed to a stress that causes them to stop eating. This lack of appetite can become so severe that a feeding tube needs to be put in.

    Keeping the blood glucose level as close to euglycemia as possible will help minimize this complication. Again, the need for periodic blood glucose monitoring along with a routine blood panel every 3-6 months become obvious.

  • Somogyi Effect (Insulin Induced Hyperglycemia)

    Overdosing the morning dose of insulin can cause hypoglycemia. If the hypoglycemia becomes severe enough (< 60 mg/dl) the body will go through complex compensatory mechanisms to raise the blood glucose level. These mechanisms involve the liver, glucagon and epinephrine. If these mechanisms are unable to raise the blood glucose rapidly enough then the symptoms of hypoglycemia described above might occur.

    When these mechanisms are able to correct the hypoglycemia they can cause the blood glucose level to go quite high later in the day and persist through the night. If the urine glucose is measured just before the morning dose the next day there will be significant glycosuria due to the previous afternoon and evenings hyperglycemia. This will cause many people to increase the insulin amount in the morning dose. This overdosing will again cause hypoglycemia some time during the day, and the cycle will repeat itself.

    This problem is diagnosed by a blood glucose curve in the hospital. A cat with the Somogyi effect will have a blood glucose level that is abnormally low some time during the day. This emphasizes the need for a blood glucose curve to monitor your pet’s problem because only one blood glucose test during the day might miss the hypoglycemia episode that is causing this problem in the first place.

    Insulin antagonism

    Pets that are not regulated in spite of higher than normal insulin doses might have this problem. This problem can mimic improper storage, handling, and administration of insulin.

    There can be many causes to insulin antagonism. Hormones, cortisone, the Somogyi effect, adrenal gland disease, infection, chronic pancreatitis, kidney disease, cancer, anti-insulin antibodies, and even ineffective insulin all could be involved. Cats that get Feline Acromegaly, an excess of growth hormone, can also get insulin resistance.

  • Infections

    Diabetic pets are prone to infections, especially of the urinary tract. These infections makes them more prone to DKA and insulin antagonism. Good dental hygiene is critical also since many pets with diabetes have dental disease. Chronic dental disease can make regulation almost impossible.

  • Cataracts

    Almost all dogs with diabetes mellitus will eventually develop cataracts. The earlier the diagnosis is made the greater chance your dog’s blood glucose can be regulated to stave this off. One of our doctors might refer you to a veterinary ophthalmologist because there can be inflammation associated with this called uveitis. The cataract needs to be removed in this case to prevent pain and further complications. Your dog has to be properly regulated regarding insulin levels before the ophthalmologist can do this surgery.

Boarding a Pet with Diabetes

It is always preferable to keep your diabetic pet in its normal environment. When this is not feasible special precautions need to be taken if your pet is boarded. Cats that board away from home are at an increased risk of becoming unregulated as to their correct insulin amount. They will frequently have a diminished appetite, increasing their chance of hypoglycemia if their insulin dose is not adjusted. Your cat should be boarded only at a facility that is adept at treating this disease and can run a blood glucose curve in case of a problem. One of the more common reasons we board pets at our hospital is because they need this type of medical monitoring for their problem.

A fructosamine test should be performed just prior to boarding for us to get an accurate idea of your pets average blood glucose level.

You should bring your food and your insulin to the boarding facility. A feeding schedule with amounts of food and water consumed and at what times should be provided. Also include a timetable when insulin is given and at what amount.

Since diabetic pets should be monitored with a blood glucose curve periodically this is an ideal time to run this test. Many cats will adapt to their new environment in a short time, which should make their individual blood glucose tests more reliable. When your return to pick up your pet we will review this curve with you and adjust doses as needed.

Summary

It is obvious that this is a complex disease that requires diligence on your part for proper control. Since every pet is different, your doctor will make a custom plan that will work for you and your pet, and will not necessarily follow any pre-established protocol. Be prepared for constantly changing insulin requirements and potential complications. The more consistent you are with feeding the same food, in the same amount, at the same time(s) every day, will add to a successful outcome.

The majority of diabetic pets on insulin therapy have a significantly increased quality of life. This usually makes the time time and monetary commitment necessary for proper regulation well worth the effort.

Continue Reading

Disk Disease (IVD)

Disk disease occurs in cats and dogs, with the occasion problem in other breeds. Since it occurs mostly in dogs, this page will emphasize disk disease in dogs, although the diagnosis and treatment of disk disk applies to cats and other species as well.

Breeders have selectively bred dogs over many years to obtain a certain look or to enhance specific qualities. One of the more significant tradeoffs with this breeding is the propensity for some breeds to have problems with their bone structure. In some dogs this affects the spinal cord.

At a minimum it causes discomfort, but unfortunately, it can cause more severe problems, including complete paralysis. When it occurs it is called intervertebral disk disease (IVD). It is one of the most common diseases causing paralysis of the rear legs in dogs.  It is estimated that up to 18% of dachshunds will have this problem. Even though it does occur in cats it is not a common disease in this species.

Neuroanatomy and physiology is a world unto itself, and is far too complex to cover completely in this page. It will be summarized and generalized for much easier understanding.

One of the most significant treatment modalities for IVD is called VNA, especially since no drugs are involved. We will talk about it more in the treatment section.

It is helpful to be aware of some of the medical terms involved with IVD:

analgesia- lack of feeling or pain hemi paresis or paralysis- problem with the front and back limb on the same side.
ataxia-incoordination para paresis or paralysis- problem with both pelvic limbs
paresis- partial paralysis mono paresis or paralysis- problem with just one limb
plegia- complete paralysis tetra paresis or paralysis- problem with all four limbs

Vertebral Anatomy

The dog has 31 vertebrae:

  • Cervical (neck)- 7
  • Thoracic (chest) – 13
  • Lumbar (lower back) – 7
  • Sacral (pelvis) – 3 (fused)

Let’s go on a tour of this anatomy by looking at overlapping radiographs:

The 7 cervical vertebrae are quite flexible, for obvious reasons. Disk disease can occur anywhere in the cervical vertebrae. C-1 and C-2 are called the atlas and the axis. There can be an instability in this area in large dogs that will cause neurologic problems. The term breeders use for this is “wobblers”.

As the cervical vertebrae become the thoracic vertebrae they go past the shoulder (S). The nerves that come off this cervical-thoracic junction at the shoulder are called the brachial plexus (you cannot see nerves on a plain radiograph). They innervate the front legs on each side. Each of the thoracic vertebrae corresponds to a rib (R) on each side of the chest.

As we continue down the thoracic vertebrae you can visualize how high their dorsal spinal processes are. Also notice how these processes start to get smaller as we get closer to the lumbar vertebrae. Thoracic vertebrae in this area do not typically cause disk disease.

Moving towards the end of the thoracic vertebrae we come to what is termed the thoracolumbar (T-L) junction. It is a very common area to have disk disease. As we pass into the lumbar vertebrae we have now made our way into the lower back.

The 7 lumbar vertebrae eventually lead into the sacral vertebrae. The fused sacral vertebrae are hard to visualize because they are within the pelvis. After the sacrum we are at the tail. The section between the last lumbar and first sacral vertebrae is called the lumbosacral (L-S) junction. Disk disease and arthritis here can be quite painful.

Spinal anatomy

The spinal cord is an extremely sensitive part of the nervous system. In essence, it is an extension of the brain. As the spinal cord moves from the brain down to the tail it sends out nerve branches (called nerve roots) that go to various organs. Some of these nerve branches bring sensation back to the brain. If you are painfully pinched on your skin it is the nerve branches in your skin that relay a feeling of pain from the skin, to a local nerve branch, and eventually along your spinal cord to your brain.

At the same time that these nerve impulses are going to the brain to tell you it hurts, there are other nerves in the spinal cord that go to the muscle near the area of pain and cause a reflex movement away from the pain. The nervous system is so sophisticated and sensitive that it actually stimulates your muscles to contract so you can move away from the painful stimulus without your brain having to tell the muscles to contract. Your brain perceives the pain, but by the time you feel the pain your muscles have already contracted.

These nerve branches that come off the spinal cord are very complex and overlap with other nerve branches. This makes localization of the exact nerve branch that is causing the problem a complex diagnostic problem. Added to the fact that our patients do not talk to us, the diagnostic challenge in figuring out exactly where on the spinal cord a dog is having a problem is no simple undertaking, and sometimes needs the aid of a specialist.

This side view of a spinal cord model shows 2 vertebrae (V) with a normal disk (D) in between. One of the nerve roots (NR) can be seen coming off of the spinal cord (SC). The head is towards the left, the tail towards the right.

To keep you oriented, this is the same area on a radiograph (at L1-2). The nerve root comes out of the dark structure that looks like a horse’s head. The disk, nerve root, and spinal cord do not show up normally on a radiograph. If the disk material becomes calcified it might show up.

This view of a spinal cord model is an end-on view of how the spinal cord fits into the spinal canal. You can see how the spinal cord is enclosed by bone. If it swells it has no place to expand into, resulting in serious damage to the cord.

Pathophysiology of IVD

Classification

  • Type IIt occurs commonly in chondrodystrophic (poor cartilage and long bone development) breeds starting as early as 4 months of age.

    The disk loses its moisture content and starts to mineralize. The stresses of daily living, especially jumping up and down,  cause it to degenerate, ultimately rupturing its contents into the spinal canal and putting pressure on the nerve roots and spinal cord. The pressure can be so great that the blood supply to the spinal cord can be damaged also, leading to actual death of spinal cord tissue (myelomalacia). Once this starts there is no treatment, and these dogs will become paralyzed and die of respiratory failure.

    In IVD disease the disk material (red) in the space between the vertebral bodies puts pressure on the spinal cord and the nerve root that is leaving the spinal cord.

  • Type IIThis version of IVD occurs in larger dogs starting around 5 years of age. The changes in the disk occur much slower than in Type I disk disease. The disk bulges but does not actually rupture into the spinal canal. The spinal cord is not as severely injured and usually maintains its normal function. These dogs tend to show chronic pain and paresis.

The above classifications are helping in understanding IVD, but they do not always apply in every case. Large breed non-chondrodystrophic dogs can get Type I disk disease, and chondrodystrophic breeds can get Type II disk disease.

Degree of Damage

It is important to note that the speed at which a ruptured disk extrudes its material into the spinal cord is equally as important as how compressed the spinal cord becomes. Some dogs with minimal compression of the spinal cord can have severe neurologic problems because disk material extruded rapidly and severely damaged the spinal cord.

Cause

Trauma to a normal disk can cause disk material to extrude into the spinal canal. The most common cause is the natural degeneration of the disk that occurs in the chondrodystrophic breeds when young, and the larger breed dogs as they age. In most chondrodystrophic breeds it is the thoracolumbar area, the junction of the last few thoracic vertebrae and the first few lumbar vertebrae, that are involved.

Symptoms

The symptoms that occur vary from mild to severe. Much of it depends on which vertebrae is involved, how long the problem has been present, and whether the problem is Type I or Type II. It is important to follow the diagnostic process carefully when making a diagnosis.

The cervical (neck) vertebrae tend to have larger spinal canals for the spinal cord to pass through than do the vertebrae of the mid and lower back. When a disk puts pressure (whether Type I or Type I) the spinal canal has more room, so the spinal cord is subject to less compression in the neck than in the mid and lower back. Less compression means there is less of a chance that paresis or paraplegia will occur.

The following symptoms tend to occur with cervical disk disease:

  • Crying- especially when the neck is manipulated or when lowered to eat or drink
  • Poor appetite (anorexia)- pain can sometimes be so severe as to interfere with appetite
  • Muscle spasms and reluctance to move- another sequelae to the pain that can occur
  • One or both front legs might be lame- nerves to the front legs come out of the spinal canal at the cervical vertebrae.
  • Ataxia- pressure on the spinal canal at the cervical vertebrae can interfere with the nerves that innervate all 4 legs. Only rarely will this cause tetraplegia (paralysis).

When IVD occurs at the junction of the thoracic and lumbar (thoracolumbar) vertebrae, symptoms might be different than in the cervical version. Some of these symptoms depend on whether there is a Type I or Type II problem.

  • Crying in pain or shaking- a consistent symptom noticed by owners is their dog crying as if something hurts. It might happen spontaneously, or it might happen when you pet or pick your dog up. Those of us that have had a pinched nerve understand how severe this pain can become.
  • Reluctance to move- this might manifest itself as a hesitation to jump onto the bed, reluctance to go up or down stairs, or just laying around more than usual.
  • Poor appetite (anorexia)- the pain that occurs can decrease the appetite.
  • Ataxia to rear quarters- a dog might walk around as if the back end is going in a different direction than the front end. This is caused by pressure on the nerve roots that go to the rear legs.
  • Paraparesis or paralysis to rear legs- the pressure on the nerve root can become so severe that it can completely impair the nerve and cause paralysis.
  • Tense abdomen- this is called referred pain, and can mimic the symptoms of other diseases.
  • Hunched appearance- an additional problem related to pain
  • Fecal or urinary incontinence- these are relatively severe signs of thoracolumbar disease

This dachshund is exhibiting signs of pain to its rear quarters. His tail is between his legs and his abdomen is hunched up.

This dog is “down” in his rear quarters, a potential sign of IVD disease.

This dog is exhibiting serious signs of IVD. It is partially paralyzed in its rear legs.

When the problem progresses to this point these dogs commonly will not be able to urinate. The urine needs to be manually expressed before it passively overflows. Urine that stagnates in the bladder causes discomfort, stretches the muscles in the bladder wall so much so that muscle tone will not return, and sets up the stage for a bladder and kidney infection. This arrows outline the distended urinary bladder of a dog with this problem.

Diagnosis

Since the symptoms of IVD disease mimic those of other diseases, a thorough approach is needed to differentiate them. In every disease we encounter we follow the tenet’s of the diagnostic approach to ensure that we make an accurate diagnosis and that we do not overlook some of the diseases that are also encountered in pets as they age.

  1. Signalment

    IVD disease can occur at any age, although it tends to be a problem that affects middle aged and older dogs.

    Several canine breeds are prone to getting IVD. They are called chondrodystrophic due to the shape of their bones from breeding:

  2. History

    IVD disease is suspected in any pet that has some of the symptoms described above, especially if the dog seems in pain or has some degree of paralysis. Falling or being hit by a car gives us a clue that the spinal cord might be damaged.

  3. Physical Exam

    Routine physical exam findings might include:

    • Shaking
    • Increased heart and respiratory rates
    • Pain upon abdominal palpation
    • Pain when moving the neck
    • Weakness to the back end
    • Lameness to any of the legs

    During your dog’s exam you will notice one of our doctors checking some reflexes. This exam helps localize the problem and helps to verify that the problem is indeed IVD and not some other problem. Four of the more common neurologic tests will be explained:

    1. Panniculus

      This test is performed by poking the skin gently with a needle. If the pin is felt the muscles underneath will cause the skin to temporarily “crawl”. By finding the junction where the skin no longer crawls it is possible to help localize the nerve root (remember, they overlap). The affected nerve root is usually 1-2 vertebrae in front of the spot where the skin crawls.

    2. Proprioceptive deficits

      This is a postural reflex that tests the ability of a dog to recognize the placement of one of its limbs without actually seeing it. This tests the ability of the nerve to respond to the abnormal sensation to a foot that is bearing weight on the wrong surface.

      When the wrong surface is bearing this weight it sends a signal from the nerves in the top of the foot to the spinal cord segment innervated by that foot. When the signal gets to the spinal cord segment it also travels to the brain signaling that the foot is in an abnormal position. The brain then sends a signal back down the spinal cord to the muscles that innervate the foot telling them to contract and put the foot back into normal position.

      This is a sensitive test, and if a dog does not return its foot to a normal position immediately it potentially indicates a serious problem with the spinal cord.

      It is easily performed by placing the foot in an abnormal position. This dog should have returned its foot to a normal position immediately. Other diseases besides IVD can cause this problem (ex.- a fractured leg)

    3. Knee jerk (myostatic)reflex

      This is a spinal reflex that tests the ability of the spinal cord to react to stretching of the patellar tendon. If absent or diminished it indicates a potential problem with the nerve root. If exaggerated it indicates a potential problem with the spinal cord. Other tendons besides the knee can be checked for this reflex.

      Every pet has a different response to this stimulus, so it is usually repeated for accuracy.

    4. Deep pain (withdrawal) reflex

      In this reflex a toe is pinched, which normally will result in withdrawal of the limb away from this painful stimulus. This occurs independent of whether or not the pain is perceived at the brain level (you already learned this at the beginning of this page in the spinal cord anatomy section). A pet with a problem in its spinal cord will have the reflex, but will not realize it is painful because the nerves that travel along the spinal cord to the brain are injured.

      Dogs that show no reaction when a painful stimulus is applied to their legs are considered to have severe spinal cord injury. These dogs carry a poor prognosis for recovery, and most need immediate surgery.  This is a subjective test though, and needs to be performed numerous times for proper interpretation. Some dogs don’t consciously show signs of pain, so this critical test can be misinterpreted.

  4. Diagnostic Tests

    Radiography

    In some cases a radiograph is the diagnostic test of choice. Radiographs help determine if a dog’s pain or paralysis is due to IVD or some other cause. Other causes can include trauma, tumors, cysts, or infections of the vertebrae.

    Dogs that have IVD might have calcified disks, collapsed disks, even calcified disk material in the spinal canal. Dogs that are radiographed for IVD disease must be under sedated or under general anesthesia for proper technique and positioning.

    This dog has spondylosis, which is a form of arthritis due to instability of the vertebrae. This is not necessarily IVD disease. Some dogs with this arthritis are in pain and need medication, while others have no symptoms at all. Cats can get spondylosis also, although it is more common in dogs.

    This radiograph of a Pug shows a collapsed disk along with spondylosis between L- 2 and L- 3. You can tell it is collapsed when you compare it to the width of the disk in front and behind.

    This dog has IVD disease. There is calcified disk material in the spinal canal between L-2 and L-3, and it is painful and weak in its rear legs.

    This radiograph is from an 11 year old dog that is weak on one of its rear legs. The arrow points to the involved vertebrae. Foreign bodies and infections are possible causes, but most likely it is a tumor. What the owner that was a “tweaked back” on their pet turned out to be a tumor, emphasizing the importance of radiography in diagnosis.

    This is the same dog but from the VD view.

    Myelogram

    As good as an x-ray is in making this diagnosis, it does not give all the information needed in some cases. Plain x-rays do not allow visualization of the actual spinal cord or nerve roots. The dye injected during a myelogram outlines the spinal cord and allows much better visualization of any pathology in the cord. Injecting a radiopaque dye into the spinal canal is  of critical importance if surgery is contemplated.

    This myelogram is outlining the spinal cord in the lumbar vertebrae of a dog. The vertical column of dye at the top is where the needle was inserted to inject the dye. Now we can actually visualize the spinal cord itself.

    Magnetic Resonance Imaging (MRI)

    This tool is available to veterinarians and is very valuable in making a diagnosis of spinal cord disease. If the myelogram is inconclusive the MRI can provide valuable information on the health of the spinal cord.

    Cats can get spinal lesions also. This is the radiograph of a 15 year old cat with a lesion in its spinal canal at the arrow. This cat is painful and not walking well on its rear quarters.

    This is the x-ray and MRI report on this same cat

Treatment

Treatment depends on the severity of the problem and whether the problem is Type I or Type II. Fortunately, in many cases, especially if caught early, conservative therapy can be beneficial. Pets that have recurring problems might eventually need surgery.

  • Cage Rest

    This is the most important treatment modality short of surgery. Cage rest means exactly what is says; there can be no running, jumping, or playing. A crib or playpen will not work because dogs will try to jump out. It sometimes has to be utilized for several weeks for an adequate outcome.

    Dogs that are cage rested need to be monitored carefully for progression of the problem. Serial neurologic exams are used to monitor their condition. They should be hospitalized for the first few days in order to monitor their progress.

  • Medication

    Anti-inflammatory and analgesic medications are used routinely in Type I disease. Medications are highly beneficial in reducing pain and minimizing inflammation at the delicate spinal cord. The mainstay when it comes to medication is cortisone.

    Muscle relaxants are also used to minimize the spasms that accompany this problem. It is imperative that any pet with IVD that is put on medication is under strict cage rest. Pets that feel better with medication might be inclined to resume their normal activity, greatly increasing the chance that their spinal cord will suffer more damage.

    Our goal is to give just enough pain medication to make the dog more comfortable, yet not so much that the dog resumes its normal activity. If a dog’s condition improves with cage rest it should be continued for up to 3 weeks. Exercise should be restricted for an additional 3 weeks. Unfortunately, recurrence is common.

    Dogs that are unable to urinate properly due to this disease might also be put on antibiotics to prevent urinary tract infections.

    Dogs with Type II are routinely placed on anti-inflammatory medication. There are many highly effective ones available to veterinarians that greatly enhance a dog’s quality of life. You can learn more about these medications, called NSAID’s (Non steroidal anti inflammatories) in the treatment section of our arthritis page.

  • Surgery

    Surgery is the treatment of choice for recurring problems, dogs that have not improved with conservative therapy, or those that have neurologic deficits. Dogs that are paralyzed (paraplegic) in the back legs need immediate surgery. During the surgery the goal is to relieve the pressure on the spinal cord. This is done by removing a piece of the vertebral body or cleaning out the disk material that is putting pressure on the cord.

    Surgery is also used to verify a diagnosis since the actual spinal cord can be visualized. In addition, even if the prognosis for recovery from paralysis is poor, surgery can minimize pain at the spinal cord if an owner is willing to deal with the long term paralysis.

    Post operative care is important in dogs undergoing back surgery. They might need hydrotherapy, manual expression of their bladders, controlled walking with assistance, and lots of TLC.

    This chart gives an idea of how these treatment modalities are used. These are not hard and fast rules, but more of a guideline.

    Medical Therapy Surgical Therapy
    First episode of pain only Several episodes of pain only
    First episode of paresis or mild ataxia Several episodes of paresis or mild ataxia
    Medical conditions that prevent surgery Condition that worsens with only medical therapy
    Paralyzed and no deep pain response for > 48 hours Mild paralysis with deep pain response present
    Symptoms of progressing myelomalacia Paralyzed and deep pain response present for less than 48 hours

    A paralyzed dog can lead a very high quality of life. These dog carts work quite well.

  • Acupuncture

    A relatively new treatment modality for IVD in dogs is acupuncture. It can be helpful in dogs that are not paralyzed or in those where anesthesia or surgery are contraindicated. It is important to remember that it does not always work, and the prolongation of other treatment modalities should not be undertaken due to the severe and potentially irreversible nature of this disease.

    Dr. P wanted to make sure the needle did not hurt an already painful dog, so he volunteered to be the “pain guinea pig”. He is happy to report that there was no problem (and he could now actually dunk a basketball!).

    Here are the needles in use in addison (the Pug whose x-rays you saw previously).

  • VNA

    In the last few years our doctors have been using this treatment method in almost every case of IVD when the pet is not paralyzed. It has changed the way we look at this disease, and give us a new tool to treat without the use of drugs. Our VNA page has more details.

Prevention

Since this seems to be a heritable disease it is theorized that screening of dachshunds at 2 years of age with radiographs, looking for disk calcification, can be an early indicator for IVD. Keeping these dogs out of the breeding pool might decrease the incidence of this disease. This is similar to taking radiographs for hip dysplasia at 2 years of age to screeen for this problem before breeding.

Prognosis

IVD is a serious and potentially crippling disease. If your dog exhibits any of the previously described symptoms it needs an immediate exam by one of our doctors. If the problem is caught early enough the outcome of this disease is usually satisfactory. If you own one of the breeds that is predisposed to this disease it is important to closely observe for the symptoms of IVD disease.

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Ear (aural) Hematoma

On occasion we are presented with a pet that has a swollen ear. The swelling is due to blood vessels that have ruptured inside the ear flap, between the inside and outside layer of cartilage. This causes the ear to fill up with bloody fluid and after a period of time the blood in the ear clots and there is a firm swelling. If left untreated the ear will be painful and will eventually scar down, similar in appearance to a cauliflower ear in a prized fighter that has spent a lifetime in the boxing ring.

Symptoms

The symptoms of an aural hematoma are obvious. Depending on the severity of the problem there will be swelling, which is sometimes extensive. Almost every pet will either be holding the head to one side or either shaking and pawing at the affected side.

This cat has a moderate sized hematoma.

Cause

 

Pets that paw at their ears or shake their heads vigorously, especially those with large ears, can cause a hematoma. This pawing and shaking can be due to irritants around the face and ears, or irritants in the external ear canals like infections or foreign bodies (foxtails). Food allergy is a common cause of inflamed ears, causing your pet to shake its head excessively and burst blood vessels.

 

Medical Treatment

 

In some cases we can alleviate the hematoma by removing the fluid and injecting cortisone into the ear.

This dog is having fluid drained from its ear.

Your pet will also go home with oral medication to be used for 10 days. This treatment is usually repeated in one week, although some cases are healed after the first week of therapy. Pets that don’t heal after the second treatment need surgical correction.

The initial cause of the hematoma, often times an ear infection or food allergy, will be treated simultaneously.

 

Surgical Treatment

 

We keep a close tab on important physiologic parameters for all of our surgeries. Monitors like this give us an early warning of an impending problem.

Surgery-Monitor

 

It is advantageous in most cases to use medical therapy first because there is no need for general anesthesia, there is minimal discomfort to your pet, and the cost is less than surgical correction. Surgical treatment is used in those situations in which the problem is not corrected with medical therapy.

Some hematomas are too large or involved to attempt medical treatment initially. Another reason we might perform surgical correction before attempting medical correction occurs when your pet is being anesthetized for another problem simultaneously, for example, dental disease.

The following section has pictures of an actual hematoma surgery, and includes pictures of blood and ear incisions. If you would like to pass this section up click here.

The first step in the surgical procedure is draining of the fluid in the ear. An incision is made with a scalpel blade and the bloody fluid is drained.


Since most hematomas have been present for many days prior to presentation, there are blood clots in the ear. These clots are removed with a hemostat.


When all of the blood and clots are removed the ear is ready for suturing. You can readily visualize the 2 layers of cartilage in this view.


The 2 layers of cartilage are sutured together to prevent the bloody swelling from returning. The incision is left partially open to facilitate further drainage of fluid. We also bandage the ear to the top of the head in some cases. The bandage and sutures are removed in 7-10 days. Healing progresses rapidly and the ear returns to normal in no time.

 

For well over the 15 years this  surgery is done in our hospital with the laser. Using the laser has substantial advantages over the method described above. It is highly recommended that this surgery is done with the laser, particularly because it will dramatically minimize pain during the healing process.


Once your pet has a hematoma it is possible for it to recur. You should check your pets ears daily for any recurrence, treat the initiating cause, and clean them frequently.

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Ear Infection

A common problem in dogs and cats is ear infections. A consistent cause of recurring ear infections is an underlying allergy called atopy. Another name for atopy is allergic dermatitis. Food allergies are also a cause of this recurring ear infection. Some pets have both as the cause.

There are many different causes and numerous treatment regimens to effect a cure. Since the causes tend to be multifactorial we need to address all of them for a successful outcome. Dogs tend to have more of a problem with ear infections as compared to cats.

Hygiene is of major importance both in curing the problem and prevention of recurrence. Ear infections can easily become chronic in nature, so proper therapy early in the course of the disease is important, along with long term commitment to keeping the ears clean.

Long term problems with the external ear can progress to problems with middle (otitis media) and inner (otitis interna) ears. This can cause substantial pain, equilibrium problems, and even hearing loss.

Anatomy

Dogs and cats ears differ from human ears in several significant ways. The main difference is the shape and length of the ear canal. It is longer in animals and has a downward and then inward direction. Alaso, their ears are more sensitive than ours. Cleaning them requires more effort than in people.

This picture shows normal dog and cat ear canal anatomy. The arrows show the downward and inward path of the external ear canal. The tip of the arrow to the left is pointing to the ear drum. When you clean the ears you will gently be pulling up on the external ear to straighten this canal out and allow deeper penetration of medication.

A normal dog ear has glands lining it they contain cilia to remove normal debris. This self cleaning mechanism works well for a healthy ear, not so well for an inflamed and infected ear. Cleaning this debris out of the ear canal is imperative for the bodies normal cleaning mechanism to work.

Symptoms

Pets commonly give their owners a clue that their ears are bothering them. Most pets will either have discharge, odor, or will be shaking their head. Sometimes the ear flap will become extremely swollen-this is called an aural hematoma. Pets that have a foreign body in their ear like a fox tail will be shaking their head extensively and frequently paw at the effected ear.

Causes

Ear disease is caused by many different and predisposing factors, some of them working in combination:

  • Anatomy – deep ear canals and long floppy ears are predisposing causes because they set up a warm and moist environment that bacteria and fungi thrive in.
  • Breed – Some breeds like Cocker Spaniels are commonly effected because of allergies, long floppy ears, and inbreeding.
  • Allergy – In addition to causing itchy skin and hair loss in general, allergies can also cause ear problems. Food allergy and atopy are common causes.
  • Low Thyroid – On occasion low thyroid hormone can cause ear problems.
  • Parasites – Ear mites are also a cause of ear disease, especially in cats. Also chiggers and sometimes ticks.
  • Drug reactions – Any drug can cause a reaction that inflames the ear, including some cleaning agents.
  • Hygiene – Debris and excess hair in the ear canal can cause an infection.
  • Auto immune system diseases
  • Tumors
  • Sugar Diabetes
  • Cushing’s Disease
  • Feline Leukemia (FeLV) and Feline Immunodeficiency (FIV) viruses.
  • Canine Distemper
  • Bacteria – Staph, Strep, Proteus, E. coli, and especially Pseudomonas.
  • Excessive cleaning
  • Yeast – Candida and Malazzezia.
  • Foreign bodies – debris, hair, foxtails (plant awns).Since there are many causes to ear disease an accurate diagnosis is essential to relieving the problem. Several diagnostic tests are routinely used:

Diagnosis

A routine physical exam is used on every pet that is presented with ear problems because ear infections can be a sign that there are problems elsewhere in the body. This exam is an essential part of the Diagnostic Process, and might include routine blood work.

Ear swabs are used to obtain a sample of discharge for microscopic analysis

Microscopic analysis of the discharge helps us determine if your pet’s problem is bacterial or fungal related. This analysis is performed in our office by taking some of the discharge from the ear canal, staining it blue with a special stain, and observing how many bacteria or fungi are noted.

A culture of the discharge from the ear is sometimes used as an aid to determine what bacteria or fungus is causing the problem. Since many organisms are usually grown in a culture, and some of them are normal inhabitants, this test is not always advantageous. This picture shows a culture that grew out 3 different bacteria that are common to find in the ear canal. Organism #2 (Pseudomonas) is resistant (R) to all the antibiotics that are commonly tested.

The otoscope is an important tool that allows us to visualize the anatomy of the external ear canal, including the ear drum. It is also used to retrieve foreign bodies, usually foxtails, from the ear canal, and to check for tumors. Ear infections are painful, and some pets need to be sedated before they let us examine their ears.

 

Checking for proper thyroid level is an important test in every dog that has recurring problems, especially in Golden Retrievers. This is a report from a pet that has a low thyroid level.

_D2A4435

In addition to these tests, allergy tests are utilized when they are suspected as the cause of the problem. A blood sample is taken that tests for allergies to food, commonly found material inside of your house, and plant like materials found throughout our area in the outdoors. Your doctor will let you know if this test is needed.

Treatment

Each ear infection requires specific treatment depending on the results of the physical exam and diagnostic tests. If there are underlying problems your doctor will prescribe medication to prevent them. In the overwhelming majority of cases medical care is all that is needed. Surgical correction of an ear infection is usually used only after medical care has been unable to control the problem.

If your pet has recurring ear problems we need to control the allergy that is likely causing this. If it is atopy, there are many things we can do to either prevent exposure to the allergen causing the problem. Food allergy is a common cause of recurring ear infection, so a trial of Hill’s Z/D or D/D will be indicated. Our Allergic Dermatitis page has all the details.

For the majority of ear infections proper cleaning and routine topical medication will correct the problem. Learning how to clean your pet’s ears is crucial. Once you have an ear infection under control, which takes 3-7 days in most cases, your goal should be to clean your pet’s ears once or twice each week in order to prevent recurrence. Infections that continually recur are very painful and substantially decrease your pet’s quality of life.

In many mild cases we are able to clean the ears in our office without sedation. After we perform the initial cleaning in our office your job at home will be much easier. You will need to clean them at home to effect a cure and prevent recurrence. You do not clean them if our doctor is using Osurnia. Our nurses will demonstrate exactly how to do this with your pet. To learn the technique click here.

For pet’s with ears that painful to clean we will anesthetize them and thoroughly, yet gently, flush the debris out and instill medication. This is a huge start in your hygiene protocol at home.

Your doctor will routinely prescribe two medications. The first is used to gently clean the ear canal and remove debris and infection. The second medication is a combination preparation that kills either bacteria, fungi, or parasites. These medications usually contain an anti-inflammatory preparation to soothe the ear also. Occasionally your doctor will prescribe oral medication to clear up the infection and to decrease the inflammation in the ear canal.

We have many medications available to us that are very convenient at treating ear infections for dogs where daily cleaning and medicating is a problem. One of them is called Osurnia.

IMG_0001

Once we clean the ears we place this medication in the ear using the premeasured single-dose tube.  It contains three ingredients that are beneficial to clear up the infection, both bacterial and fungal,  and also sooth the ear. That is all you have to do for one week. In one week we recheck the ear to make sure the infection is getting under control, then we place another tube of medication in the ear. If your pet has no underlying problems as described above the infection is usually cleared up, and you don’t need to clean and medicate the ears daily. The ears are not cleaned again until 45 days have passed.

Many dogs have hair inside of the ear canal. If your dog is not having any ear problems this hair is left alone. If this hair is causing a problem it is removed to facilitate cleaning and to let air circulate into the ear canal. This should be done routinely, which for most dogs is at least once monthly. These ears are typical of a pet that needs the hair removed from its ears and a thorough cleaning. Sometimes just removing the hair from the ear canals completely corrects any problem, so please keep them hair free at all times.

These are the same ears after one of our nurses has cleaned them. It is obvious from the picture that this pet will feel much better from this treatment. It is a common sense approach and does not require any medication.

In some pets the ears are so inflamed that its painful to clean the ears. In these severe cases we use sedation and flushing. A warm cleansing solution is used to remove debris and infection from deep within the ear canal by flushing action only. These ears are painful and we need to go gently so as not to cause more pain and damage to an already severely inflamed ear canal.

This ear has had recurring infections for so long that it is no longer possible to clean the external ear canal. The canal is swollen shut, infected and very painful. The only adequate remedy in this case is surgical correction to completely remove the ear canal. It is extensive surgery and requires a surgeon with specialized training and expertise. The goal of long term ear care is to never let the disease progress to this point.

Here is another dog with the same problem as it is prepped just prior to surgery

 

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Hip Dysplasia

Hip dysplasia is a congenital disease that affects mostly large breed dogs, although any breed can get it, and even cats can have a problem with their hip sockets.

Hip dysplasia is a laxity in the socked of the hip joint where the head of the femur fits into the pelvis. It causes weakness and lameness to the rear quarters, and eventually leads to painful arthritis. This arthritis goes by several names; degenerative joint disease, arthrosis, osteoarthritis.

This disease is so prevalent, and so debilitating, that a special veterinary organization called The Orthopedic Foundation for Animals (OFA) was organized to minimize the problem in the breeding pool of dogs. It occurs rarely in cats, primarily the Maine coon, and usually in females.


Cause

Many factors work together to cause this disease, which is a combination of a dog genetically inclined to get this disease interacting with environmental factors that bring about the symptoms. These environmental factors excess calcium in the diet of puppy food for large breed dogs, along with obesity, high protein and calorie diets, and a lack of or too much exercise. The breeding of dogs that already have hip dysplasia is one of the primary reasons the disease is still present. A dog that has hip dysplasia in one socket is prone to having a problem with the ligaments of the knee in the other leg (anterior cruciate rupture).

Pathophysiology

During the degenerative process the cartilage that lines the hip joint, called hyaline cartilage, is damaged. The damage results from the abnormal forces on the cartilage from the deformed hip socket. Small fractures can occur in the cartilage also. Eventually an enzyme is released that degrades the joint further and decrease the synthesis of an important joint protectant called proteoglycans. The cartilage becomes thinner and stiffer, further compromising its ability to handle the stresses of daily movement and weight bearing.As the problem progresses more enzymes are released, which now affect the precursors to proteoglycans, molecules called glycosaminoglycans and hyaluronate. Lubrication is negligible, inflammation occurs, and the joint fluid can no longer nourish the hyaline cartilage. This viscious cycle continues until pain occurs. The body attempts to reduce this pain by stabilizing the hip joint. New bone is deposited at the joint, both inside and out, along with some of the ligaments and muscle attachments to the area. This causes thickening and a decrease in the range of motion. This is the actual arthritis noted on a radiograph, which will not go away, and will continue to progress.

 

Breed Predispositions

Many dogs can develop hip dysplasia. Dogs that were commonly affected years ago, like German Shepherds and Labrador Retrievers, still get the disease but not as commonly as before.

According to the OFA some of the breeds with the highest prevalence are:

Bulldog Pug Otterhund Clumber Spaniel
Neapolitan Mastiff St. Bernard Boykin Spaniel Sussex Spaniel
American Bulldog Newfoundland American Staffordshire Terrier Bloodhound
Bullmastiff Chesapeake Bay Retriever Golden Retriever Gordon Setter
Rottweiler Chow Chow Old English Sheepdog Kuvasz
Norweigan Elkhound Giant Schnauzer German Shepherd Bernese Mountain Dog
English Setter Black and Tan Coonhound Shih Tzu Staffordshire Terrier
Welsh Corgi Beagle Briard Brittany
Bouvier des flandres Welsh Springer Spaniel Curly Coated Retriever Polish Lowland Sheepdog
Portugese Water Dog English Springer Spaniel Pudel Pointer Irish Water Spaniel

Diagnosis

Hip Dysplasia is diagnosed based on a history of weakness or lameness to the rear legs, especially after exercise or when first getting up after resting. Some young dogs will bunny hop when running, and might lie down on their stomachs with their legs stretched behind them. It is possible to palpate joint laxity on some dogs that are anesthetized (we call this the Ortolani sign). Sometimes we will feel grinding, called crepitus, in the hip joint as we move the leg around the socket.

Radiography is the definitive way this disease is diagnosed. It is not perfect though, since a dog can be hip dysplasia free on the radiograph (phenotype), but can be genetically predisposed to the disease (genotype). These dogs have the potential to be carriers of the disease, yet show no symptoms themselves.

Many variables affect the degree of lameness. They include age of onset, caloric intake, degree of exercise, and weather. To further add to the complication, pets with terrible looking hips on radiographs might act as if nothing is wrong, while others with barely discernible changes on their radiographs might be severely lame.

These are the x-rays of a dog with a normal pelvis. The diagram below explains why these hips are normal. View both of them at the same time if possible.

On the right side of this normal pelvis we have outlined 2 important anatomical features. The “U” shaped appearance of the neck (outlined in white), and the full rounded appearance of the head (outlined in black), are normal. They indicate a full socket with a tight fit and no signs of secondary changes due to instability of the ball and socket joint.

Here is a larger view of normal hips with digital radiography you can click on to see more detail

Normal-hipsweb

This dog has moderate changes that indicate it has hip dysplasia on the right side. The socket is not as rounded as it could be, and the head of the femur is slightly flattened. also, the neck of the femur does not have the U shaped indentation that is normal. You can see this better on the closeup views below.

 

The arrow points to the thickening in the femoral neck in the abnormal right socket. You can also visualize the slightly flattened appearance of the head of the femur and the fact that it does not fit into the socket as tight as the normal hip marked left.

This is a case of severe hip dysplasia. The arrows point to the thickened femoral neck on each side along with the secondary arthritis occurring on the left side. Notice how flat the sockets are and the lack of rounded appearance of the femoral head. This dog is probably in pain and has a difficult time walking in the rear quarters.

If left untreated the disease continues to progress, eventually causing a crippling lameness and severe pain. Correcting this problem at an early age might have prevented this.

These digital radiographs show even more detail on a dog with moderate hip dysplasia radiographically. The arrows point to boney projections from the pelvis. This is painful secondary arthritis forming due to the instability of the hip socket.

BadHipsarrowsweb

This is a another digital radiograph of even more advanced secondary arthritis in a dog with severe hip dysplasia

SevereHipDysplasia

Dogs are not the only species that gets hip dysplasia. It can also occur in cats (Maine Coons are commonly affected), although not as common as in dogs.

The white arrows outline the large amount of stool in the colon of the above cat with feline hip dysplasia. It is painful for this cat to squat to have a bowel movement, as a result it gets severely constipated.

Other diseases that cause lameness or soreness in the rear legs can mimic hip dysplasia. These include rupture of the cranial cruciate ligament in the knee, panosteitis, and degenerative disease of the spinal cord affecting the nerves to the rear legs.

Medical Treatment

Medical therapy might help in some cases. It depends on the size of your dog, what its function will be in your household, age, and severity of the problem. You might need to try several treatments until you find the one what works. Many of these treatments need to be used in combination with other medical therapies. Please keep in mind that large breed dogs are stoic. Do to their propensity to please you, these dogs can see fine on the outside but are painful on the inside. Watching for subtle signs is important.

Medical therapy will not cure the problem, and in most cases painful arthritis will set in. Early surgical intervention is usually the best course of action. It is not uncommon to radiograph your dog’s pelvis when it is already under anesthesia for a spay (OVH or ovariohysterectomy) or neuter.

Environmental

Keeping your dog’s weight under control and providing controlled exercise are very beneficial. Going for short walks will give you an idea of your dog’s limits. Proper exercise will maintain muscle tone and keep the joints moving and more fluid. Provide a warm environment and a well padded bedding area are also of benefit. Additional warmth helps chronically infected joints. Hot water bottles are helpful. We don’t recommend electric heating pads because of serious burn potential.

Swimming in a pool if your dog is comfortable with it can be beneficial. Hydrotherapy in a tub supervised by a veterinary certified in rehabilitative medicine is also helpful.

Non-Drug

Acupuncture, Laser Therapy, and VNA are excellent treatment choices in many cases because they are effective without the use of drugs. Our  Alternative Medicine page has detailed information.

Gentle passive range of motion exercises might help. Use of the food J/D (joint diet) is also recommended. There is also a version of J/D called Metabolic and Mobility that decreases weight in obese dogs while also providing treatment for the arthritis. It contains extra amounts of omega-3 fatty acids which might help reduce joint inflammation. One of these foods should initially be tried on all dogs with hip dysplasia.

Drugs

Many drugs have been used to control the pain associated with the secondary arthritis that occurs with hip dysplasia. Some of these drugs are extremely effective, and can provide a dog with a high degree of relief from pain. They only mask symptoms though and do not cure the problem.

Buffered aspirin and ascriptin (aspirin with maalox) are readily available over the counter remedies. Tylenol should not be used in dogs because of its potential for side effects. Tylenol is NEVER used in cats because it can cause a serious disease called methemoglobinemia.

NSAID’s (Non Steroidal Anti-inflammatory Drugs) are highly effective prescription medications. The work by inhibiting the release of prostaglandins, leading to less inflammation in the joints. They should be given prior to any bout of exercise. Some dogs will vomit or have diarrhea on these medications. Giving the medication on a full stomach and using GI protectants like Pepcid AC can minimize this problem. Their  use in labradors should be carefully monitored for signs of liver problems. Any dog that is on these drugs long term should have a blood panel taken to monitor internal organ function, especially kidney and liver.

Nutraceuticals are popular arthritis treatments, primarily because they are thought of as more natural than drugs. Humanoids use them commonly. They provide the raw material that enhance they synthesis of glycosaminoglycan and hyaluronate. Controlled studies are lacking to determine their true effectiveness. Oral versions take at least one month to become effective. A great advantage is their lack of side effects. Oral versions include Cosequin, Synovicare, Glycoflex, arthramine, and MaxFlex. Injectable versions include adequan, a drug that has been used in veterinary medicine, especially in horses, for many years. Injectable versions achieve a more rapid response than oral medications.

We can’t predict which medications will work best in an individual case. Trying different ones, even using some of them in combination, can let you determine which is the best approach in your dog.

 

Surgical Treatment

Most cases of hip dysplasia, especially in younger dogs, are treated surgically. One of the surgical specialists we consult with will make the determination of which procedure is the most appropriate. Three main types of surgery are performed.

This area contains graphic pictures of actual surgical procedures performed at the hospital. It may not be suitable for some children (and some adults also!).

1. Femoral Head Ostectomy (FHO) or Excision Arthroplasty

In this procedure the head (or ball) of the femur is removed. The remaining part of the femur forms a false joint with the muscles, ligaments, and tendons in the area. Even though this false joint is not as good as a real joint, there is a significant reduction in pain. almost any sized dog can have this procedure even though it is much more effective in smaller dogs. Obese dogs and those with significant loss of muscle do not do as well. Compared to the other types of surgery this one is much more basic, yet many pets that have this surgery return to almost normal function.

This are the hips of Mickey, a very active australian Shepherd. He has hip dysplasia on both sides. FHO surgery will be performed on his right hip.

After the skin incision is made the muscles are separated to give visualization of the femoral head. It is gently rotated and brought up as far as possible.

A special air powered drill is used to cut the neck of the femur at just the right angle.

The angle in the cut of the femoral neck is apparent. also present on the head of this femur is a piece of the round ligament, one of the structures that anchors the head of the femur into the socket.

An opening remains where the head of the femur used to reside. The remaining bone will form a false joint, and return this pet to almost 100% function.

The muscles that were separated and cut are now carefully sutured. These muscles are necessary for normal movement of the false joint that will soon form.

This is what remains after the surgery. Mickey healed rapidly after the surgery and is running around as fast as before, according to his worried mom.

 

2. Triple Pelvic Osteotomy (TPO)

This surgery is used in large breed dogs no older than 10 months of age. Candidates for this surgery can only have mild hip dysplasia and no signs of secondary arthritis. During the procedure the pelvis is cut and rotated slightly so that the head of the femur has a tighter fit into the socket. Since the pelvis is being cut it needs to be stabilized with bone plates.

The pelvis is cut in 3 locations. The locations of these cuts allows the proper rotation of the hips.

This is the final result after a TPO surgery. These two plates are angled to provide the proper pelvic rotation.

Click on this radiograph for a larger view of a TPO surgery

tpo

3. Total Hip Replacement (THR)

In this procedure the neck and head of the femur are replaced with stainless steel or titanium implants. This is a highly specialized procedure performed only by select veterinarians. It is used in young dogs that have achieved most of their skeletal growth and in adult dogs that weigh at least 40 pounds. It can be used in dogs that already have secondary arthritis, unlike the TPO. It has a high success rate but has to be performed carefully because if post operative complications occur they can be disastrous.

This is the end result of the surgery. These implants now make up the ball and socket joint, and will remain fully functional for many years.

An additional treatment modality that has yielded great success in treating hip dysplasia is called VNA. It is a non-invasive and non-painful way to stimulate the nervous system to help the hip dysplasia syndrome.

Prevention

This is achieved by neutering pets that have the disease. Dogs can be screened for this problem by taking radiographs of their hips at 2 years of age. If they are certified free of hip dysplasia by the Orthopedic Foundation of america (OFA), there is much less of a chance they will sire offspring with the problem. It is best to purchase large breed dogs only if their parents are OFA certified to be hip dysplasia free.

No guarantee can be given when breeding hip dysplasia free dogs radiographically that their offspring will not deveop the disease. A dog can be hip dysplasia free on a radiograph, yet still carry the genetic predisposition to this disease that will be transmitted to its offspring.

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Spleen Disease (Hemangiosarcoma, Hematoma)

It is not uncommon for us to encounter problems with the spleen. Sometimes it just enlarges without any major problems, sometimes it twists on itself, sometimes it causes internal bleeding, and oftentimes it becomes cancerous. This page will emphasize cancer of the spleen, called hemangiosarcoma..

In breeds that have a high incidence of splenic tumor we recommend yearly exams starting at 5 years of age,  with radiographs and ultrasounds to catch this problem early before complications and spread, since the prognosis is poor in most cancerous spleens because they have already spread by the time of diagnosis.

Unfortunately, some pets, especially large breed dogs, will not show any symptoms until the spleen is huge. This occurred with a Labrador Retriever that was presented to us with the owner telling us “he just wasn’t doing right”.  He was eating good, was not vomiting, had no diarrhea, and was not coughing. This owner was astute and brought him in for an exam just in case.

A thorough exam and blood panel revealed no problems, so a radiograph was taken. This radiograph revealed a large abdominal mass. This could have been coming from the liver, spleen, intestines, kidneys, pancreas, or mesenteric lymph nodes. An ultrasound revealed it was from the spleen. The next day we removed an 8 pound rupturing spleen! You can see pictures of the surgery to remove this large mass in the surgery section later in this page, along with pictures of a dog with an even larger spleen!

Graphic surgical photos are on this page, especially of surgery which tends to be bloody.

Nomenclature

We will use some medical terms regarding the spleen:

  • Extra medullary hematopoeisis- The making of red blood cells outside of the bone marrow
  • Reticuloendothelial system- in regards to the spleen, it is the system that recycles red blood cells
  • Anemia- a low amount of red blood cells or hemoglobin
  • Thrombocytopenia- a decrease in thrombocytes, which are an important part of the clotting factors when there is bleeding.
  • Hemoabdomen- free blood in the abdomen
  • Splenomegaly- enlargement of the spleen as a result of any cause
  • Splenectomy- removal of the spleen
  • Hypersplenism- an enlarged spleen that is normal and not causing any problem

Spleen Anatomy

The spleen is an elongated and relatively flat organ that resides in the abdomen of mammals along the outer edge of the stomach. It has a tremendous blood supply that is closely attached to the blood supply supporting the stomach. It is the largest filter of blood in the body.

It has an outer capsule composed of smooth muscle and elastic fibers. The internal part of the spleen (called the parenchyma) has white pulp and red pulp. The white pulp is lymphatic tissue and the red pulp is part of the venous blood system. In between these pulps is elastic tissue that can fill up as needed.

A normal spleen in a cat

A normal spleen in a  small dog

A normal spleen in a medium sized dog

A swollen spleen in a medium sized dog

The blood supply to the spleen is closely adjoined to the stomach. You can see the dark vertical blood vessels in this photo as they enter fat between the stomach and a very enlarged and dark spleen in a semi-circle at the far right.

Physiology

The spleen has many functions. The four primary ones are:

  • Storage of cells
  • Production of red blood cells
  • Filtration of the bloodstream
  • Production of cells for the immune system

Iron that has been recycled from old red blood cells is stored in the spleen where it awaits transport to the bone marrow.

Fortunately, the body can get by without a spleen in most cases, so if there is a serious problem, and all other factors are equal, we will remove it. We tend to remove only spleens that are cancerous, rupturing, or have a torsion.

Diseases

Splenomegaly

Splenomegaly is a generalized term that simply means enlargement of the spleen. In some species, like ferrets, an enlarged spleen can be normal, and is called hypersplenism. A spleen can be enlarged diffusely or it might  have nodules in certain areas.

There are many causes for an enlarged spleen. The most common and important are listed in more detail below. Some of the more uncommon ones are due to infectious agents (erlichiosis, babesia, hemobartonella), FIP, medications, and immune mediated diseases.

This spleen has splenomegaly in addition to numerous nodules

Splenic Torsion

In this problem the spleen twists on itself, compromising the blood supply. When the spleen twists the blood keeps on pumping into it by the arterial system, but this same blood is not able to leave through the venous system, and the spleen becomes grossly engorged.

It can occur on its own, after excessive exercise, or due to trauma. It can occur in conjunction with Gastric Dilatation Volvulus (GDV), also known as bloat. We tend to see this torsion, along with GDV, in large and deep chested breeds.

If the torsion is chronic, there might be no symptoms at all, or there might be:

    • poor appetite (anorexia)
    • weight loss
    • discolored urine
    • vomiting- might be intermittent
    • weakness
    • weight loss.
    • collapse
    • death

Examination of a pet with splenic torsion might reveal:

    • pale mucous membranes (gums)
    • rapid heart rate (tachycardia)
    • painful abdomen
    • a large mass in the abdomen upon palpation
    • fever
    • dehydration
    • jaundice (icterus)

Icterus, also known as jaundice, is a yellow discoloration

icterusgums

A blood panel might reveal:

    • anemia
    • low platelets (thrombocytopenia)
    • elevated white blood cells (leukocytosis),
    • elevated liver enzyme tests,
    • hemoglobin in the urine (hemoglobinuria)

This disease is diagnosed by imaging tests when the above symptoms are present. A radiograph might reveal a mass in the abdomen with the spleen abnormally located. Ultrasound can confirm the problem and give us an idea of its severity.

A splenic torsion is considered an emergency, so the treatment of choice is surgical removal after a pet has been stabilized by treating for shock. On the deep chested breeds we might even tack the stomach to the abdomen to help prevent potential GDV in the future.

Splenic Cancer

Some splenic masses that are cancerous are classified as benign, meaning they do not generally spread (metastasize), and only take up extra space within the abdomen. Even though they do not spread, sometimes this extra space they take up can interfere with other organs.

Some benign cancerous masses include lipoma (fatty tumors), hemagioma (associated with vasculature), and plasmacytosis (infiltration of plasma cells throughout the splenic nodule or tissue in general). Unfortunately, when a spleen has cancer it commonly is the malignant version and not this benign version.

 The most common malignant tumor in the spleen is the hemangiosarcoma (HSA). It is also called malignant hemangioendothelioma). The cause is not known. It can spread to many different organs, making it highly malignant:

      • heart
      • lungs
      • muscle
      • skin
      • bones
      • abdomen
      • diaphragm
      • brain
      • kidney

HSA can also cause complications, such as disruption of the coagulation cascade which causes a mixture of abnormal clot formation as well as inability to control internal bleeding (known as disseminated intravascular coagulation, DIC).

Symptoms of HSA vary, and range from mild to severe. In extreme cases sudden blood loss can lead to sudden death.

These large nodules on this spleen are a malignant cancer called hemangiosarcoma

Another common type of malignant splenic cancer is lymphosarcoma, a type of cancer that can have a primary tumor in any other organ (i.e. lung, gastrointestinal tract, liver). Lymphosarcoma is one of the more common tumor types observed in the spleen of cats. Sometimes the tumor within the spleen is not even the primary tumor, but rather a single nodule or multiple nodules due to metastasis from a distant primary tumor.

Hematoma

Hematomas are one of the most common causes of an enlarged spleen in dogs, representing over 50% of splenomegaly cases. This type of splenic mass is basically an accumulation of pooled blood within the splenic tissue; many stop growing and are then resorbed after a period of time, but others grow exponentially and eventually rupture. A ruptured hematoma originating from the spleen is an emergency, and often the pet experiences an acute collapsing episode followed by a significant loss of blood into the abdomen (hemoabdomen). You can see the surgery of a dog with an 8 pound hematoma later in this page

Other causes

Congestions of the spleen can occur from iatrogenic causes, which are those associated with administration of certain drugs (i.e. anesthetic agents or tranquilizers). Congestion can also occur due to increased blood pressure within the vasculature of the liver (known as portal hypertension), which can occur secondary to congestive heat failure among others.  The spleen can over-react to particular conditions, resulting in a disease process known as hyperplastic, or reactive, splenomegaly. A spleen can become reactive when there is excessive stimulation of the immune system from conditions such as immune-mediated disease, bacterial infections, tick-borne diseases, and many more.

This spleen has a laceration

Diagnosis

Signalment

Dogs, cats, and ferrets can get splenic diseases, although it is much more of a problem in dogs. Splenomegaly itself can occur in most any age due to the numerous causes of the condition. For instance, if the cause of splenic enlargement is infectious, then the pet may be quite young. However, if the enlargement is cancerous, the pet tends to be middle aged (average 10 years in dogs). Due to the wide range of causes, there is no known gender predilection (males tend to be affected equally as often as females). Certain disease processes tend to be over-represented by specific breeds:

Splenic torsion tends to occur in large breed, deep-chested dogs:

Splenic tumors like HSA tend to occur in several breeds. It can be some common in some breeds that we  recommend physical exams, blood work, abdominal radiographs, and especially abdominal ultrasounds, yearly in these dogs as they reach 5 years of age:

    • German Shepherds
    • Golden Retrievers
    • Portugese Water Dogs
    • Boxers
    • English setters
    • English pointers
    • Great Danes
    • Skye Terriers
    • Bernese Mountain Dogs

History

In many cases, a patient with splenic disease has very little or no specific clinical signs. Observations made by owners at home might include non-specific indicators of illness:

    • lethargy
    • inappetence
    • weight loss
    • diarrhea
    • vomiting
    • collapse
    • discolored urine
    • abdominal distention

Physical Exam

Upon palpation of the abdomen, significant abnormalities of the spleen can usually be detected, especially when a large mass is present within the cranial aspect of the abdomen (toward the chest). However, a mass or enlarged organ in the cranial abdomen cannot always be differentiated from a mass or enlargement of the liver. In some cases, decreased pallor (pale gums) can be a sign of anemia or shock, which in combination with an abdominal mass can indicate a ruptured splenic mass or torsion. We confirm this with an ultrasound before surgery.

If the gums are pale, certain diseases of the spleen may lead to free blood in the abdomen, which can sometimes but not always be detected by palpation of a fluid wave. Other generalized signs might include weakness, fever, dehydration, poor pulses, increased heart rate (tachycardia), increased bleeding at site of blood draw (due to coagulopathy), and/or increased size of peripheral lymph nodes.

Diagnostic Tests

Some diagnostic tests which provide significant information include radiographs, blood work, ultrasonography, evaluation of the cells (cytology) through a fine-needle aspirate sample, and surgical exploration.

Radiography

The arrow points to what a spleen looks like on a radiograph. It is enlarged, although a lobe of the liver can easily overlap the spleen and make the spleen look enlarged. So in this case, technically its called hepatosplenomegaly.

Here is a dog with an enlarged spleen. Can you see it?

Splenectomy -SpleenRadSplenectomy -SpleenRadSplenectomy-LateralRad

The red circle delineates the enlarged spleen.

L.I. – Large Intestine

Pr- Prostate

Splenectomy -SpleenRad Splenectomy-SpleenRadCircle

Blood Panel

Blood work (clinical chemistry and complete blood counts) is a crucial component for detection of compromised organ function. Splenic involvement might reveal anemia (decreased red blood cells), thrombocytopenia (decreased platelets for clotting), leukopenia (decreased white blood cells) and reticulocytosis (increased immature red blood cells to indicate that the body is trying to compensate for the loss of mature red blood cells).

This is a blood panel that might be seen with splenic disease, although many other diseases can also cause this type of blood panel. The primary problem in this blood panel is anemia.

Fluid Analysis

If abdominal fluid is present we can remove it and analyze it. This is called abdominocentesis. There is no guarantee this will make a diagnosis since many cancers, including HSA, might not be found in this fluid.

Ultrasonography

Ultrasonography has revolutionized diagnosis in animals, and prevented many unnecessary exploratory surgeries (called celiotomies or laparotomies), while at the same time alerted us to the fact that we need to do immediate surgery. Keep in mind, our patients do not talk to us, and  an enlarging tumor in the abdomen in one of us humanoids would be uncomfortable, and cause us to seek medical care long before we see a dog or cat with a tumor growing in the abdomen.

Ultrasonography of the abdomen is an important modality for diagnosis of splenic disease because of its sensitivity to changes of organ size, shape, location, and even texture. An ultrasonographic examination in combination with radiographs provides a comprehensive understanding of which organs are involved and often helps to narrow the possibilities down to a select few differentials.

We use ultrasound to confirm our suspicions of a splenic tumor based on the breed, history, exam findings, and blood panels and radiographs. Ultrasound confirms the diagnosis, lets us know if the spleen is already rupturing, tells us the size of the spleen, and if there are any other internal organ problems. A critical component of the ultrasonographic exam in HSA is echocardiography (evaluation of the heart). A key site of metastasis associated with hemangiosarcoma is the right atrium. HSA that has spread to the right atrium of the heart is a serious sign, and the prognosis is not good. This is important information if we are thinking of surgical removal of the spleen.

The lines demarcate the margins of this spleen

Do you see the spleen in this picture without the demarcation?

A typical ultrasound report on a dog with a cancerous spleen

This ultrasound of the heart (echocardiogram) shows spread of the tumor to the right atrium, which is a poor prognosis

RV- Right ventricle

RA- Right atrium

Cytology

Aspiration of the cells in an organ for cytological exam by a pathologist is an important part of most abdominal ultrasounds. It helps prevent an exploratory surgery, and can lead to a diagnosis in many cases. Cytologic evaluation of splenic problems is not always indicated and can sometimes be contraindicated depending on certain disease processes. Certain cancers of the spleen as well as hematomas may result in significant blood loss if stuck with a needle due their fragile nature. Even though the ultrasound guides the biopsy location, if the disease process only involves a small portion of the splenic tissue, or is sporadically located throughout, then a small needle-sized sample may not obtain the affected tissue at all.

ECG (Electrocardiogram)

This tests the electrical activity of the heart. I some HSA’s there will be an arrhythmia

Definitive Diagnosis

Histopathology is the analysis of the spleen after it is removed. This gives us our final diagnosis.

Histopathology

Treatment

Surgery is a common treatment for splenic disease. This is called a splenectomy. If there is trauma or a problem in only a small part of the spleen, we might do a partial splenectomy since we always want to preserve as much function of the spleen as possible. This partial splenectomy is not common.

We do the surgery to remove the tumor, and if malignant add chemotherapy to help prevent spread after we do the surgery. Prior to surgery we do an ultrasound of the heart as already mentioned, and also take chest radiographs to check for spread of a tumor. We also perform a clotting panel since blood loss is common in this surgery and we do not want post operative bleeding.

Unfortunately, survival time for dogs and cats with surgery alonge HSA is only 1-3 months, with most dogs dying due to spread of the HSA to other organs, causing these organs to malfunction. This emphasizes the need for an early diagnosis in the breeds prone to this cancer.

Dogs that have surgery to remove the spleen, and that are also treated with chemotherapy, might survive up to 9 months. This depends on whether the tumor has spread, and again emphasizes the need for an early diagnosis. Dogs and cats have less side effects than people on chemotherapy, and their quality of life is high if this therapy is instituted immediately after surgery.

Dogs that are diagnosed at a young age, have had the HSA rupture prior to surgery, have evidence of spread to other organs when the splenectomy is performed, or have a more aggressive grade of tumor, do not tend to live 9 months after surgery.

The primary chemotherapy drug for HSA is Adriamycin (doxorubicin). It will slow the disease process, but it will not cure your pet of this disease. The doctors at the Veterinary Cancer Group in Tustin institute this therapy.

If a pet is anemic, or we anticipate significant blood loss during surgery, we will give a blood transfusion prior to surgery or during the procedure. Post operatively if a pet is not doing well we will give a blood transfusion also.

After doing a cross match to ensure compatibility we obtain whole blood for the transfusion

Splenectomy

A splenectomy is performed to treat and sometimes cure this problem. It is sometimes done as an emergency procedure if the spleen has ruptured and there is significant internal bleeding.

Pre-anesthetic preparation is important in every surgery we perform, no matter how routine, because surgery is not an area to cut corners.  Once a pet is anesthetized, prepared for surgery, and had its monitoring equipment hooked up and reading accurately, the surgery can begin.

This is a sterile abdominal surgery, and our surgeons scrubs with a special antiseptic soap prior to gowning and gloving

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While our patient is being anesthetized our surgeon is already in our surgical suite setting up instruments. Our surgeon is ready to start before our patient is at a proper plane of anesthesia. Once the anesthetist gives the green light the surgery starts immediately. We want our surgeon waiting for his patient, not the other way around.  All of this is to minimize anesthetic time.

OVH-rabbit-3

OVH-rabbit-2

We keep a close tab on important physiologic parameters for all of our surgeries. Monitors like this give us an early warning of an impending problem.

This machine monitors:

Temperature

Heart Rate

Heart rhythm

Oxygen saturation

Carbon dioxide level

Respiratory rate

Surgery-Monitor

In addition to our monitoring equipment our anesthetist stays “hands on” in monitoring important physiologic parameters. In addition to our monitoring equipment our anesthetist stays “hands on” in monitoring important physiologic parameters. Our anesthetist is using a special stethoscope (esophageal), that is passed down the esophagus and lays right over the heart. This gives us a clear sound of the heart and how it is beating.

Rabbit-femurfx-9

To minimize anesthetic time we routinely have 2 doctors working as a team performing the splenectomy.  They work together as a well orchestrated team.Our patient is under anesthesia and our surgeons are completing the draping process while our anesthetist is adjusting the surgical lights.

By working together early in the surgery we minimize anesthetic time.

For a pet that might already be anemic it is important to minimize blood loss during surgery. Special care is taken on entering the abdomen to minimize loss. There is minimal bleeding at this point as our surgeon gently dissects the sub Q (subcutaneous) tissue just under the skin.

As the surgery progresses we sometimes encounter significant bleeding from blood vessels in the sub Q fat and from muscles that are cut. All of them are clamped or cauterized before proceeding further. For a pet that might already be anemic this added blood loss is important to control, and it is stopped immediately.

When all bleeders are under control (called hemostasis) we enter the abdomen. We make our incision at a specific spot in the abdominal muscles called the linea alba. It is at this spot that there are minimal blood vessels. The linea also has strong tendinous attachments to the muscle, so when we sew it back together these tendons attachments have more holding ability than the abdominal muscles alone. This will prevent a hernia.

Our first view of the spleen once we have entered the abdomen. It is the round and reddish structure at the top of the abdominal opening and just to the left of our surgeon’s finger.

A spleen that is not healthy is friable and can easily rupture when handled. Our surgeon has to gently coax it out to prevent  this from happening.

Once it is finally exteriorized the problem is obvious. At this point we do not know if it is cancerous or not. We do know it is in the process of rupturing and glad we are getting it out now.

Now that we have it ready for removal we have to ligate its blood supply. As you remember from your surgical anatomy above the blood vessels to the spleen are closely related stomach. It is important to ligate the blood supply very close to the spleen so as not to compromise the blood supply to the stomach, leading to serious consequences.

This blood supply can be surrounded by fat. We have to isolate segments before we ligate.

In the center of this picture you can see one blood vessel that is already ligated. On the right our surgeon is in the process of ligating another blood vessel.

We have completed 3 ligations at this point, with many more to go.

Our surgeons work simultaneously, each starting at a different end of the spleen, so they can complete this tedious part of the surgery sooner. Its all about secure ligation of these blood vessels and minimal anesthetic time.

As part of the natural healing process there is a tissue in the abdomen called omentum. It is like a net, and surrounds an organ that might be diseased. For example, a ruptured intestine that is leaking intestinal fluid (extremely irritating to the abdomen and will cause a peritonitis), will have this net surround the intestine to wall off the leak.

In the case of this rupturing spleen the omentum covered the spleen to help prevent further blood loss. These are clots on the omentum from that. At this point in time during the surgery we cannot determine for sure if these are clots or spread of tumor. The report from the pathologist will tell us for sure. It turns out that this time they are clots.

When the spleen is completely removed we complete our exploratory surgery by checking the other internal organs, especially the liver. Once this check is complete we suture the muscle layer (the linea alba) closed. Again, we work as a team, with each surgeon (they are both lefties) suturing the linea until they meet in the center.

Once we have finished suturing our patient, who is already on a pain patch (Duragesic or Fentanyl patch- which is removed in 3 days), is given an additional pain injection and carefully monitored post-operatively. As part of the monitoring we perform a simple blood panel to make sure there was no problem with blood loss during surgery. If the blood loss is significant we will give a blood transfusion with the blood we have already set aside specifically for this patient.

Post operatively we take radiographs of the chest and perform and ultrasound every 2 months for cases of HSA looking for distant and local metastasis.

Occasionally we come across a spleen that is so large it is hard to believe it can get this big. The following spleen was over 8 pounds, removed for a 65 pound labrador named Jake.  Dr. P and Dr. R had to do this one together. Removing it was like delivering a baby!

The size was obvious as soon as we entered the abdomen. At this point in time we were not sure if it was a boy or a girl! Dr. P is coaxing it out of the abdomen at the beginning of the surgery, being very careful not to rupture it.

We had to be very gentle  because it was quite delicate(friable) and already rupturing

Ligating the blood vessels to the spleen was more difficult than usual because of the size, scar tissue, and omental tissue that covered the rupturing spleen

It turns out that this was a hematoma and the dog did fine for several more years. Lucky this spleen did not rupture before the surgery.  Most likely, with a hematoma this large, death would have ensued rapidly.

We also took out a spleen with a large hematoma on this dog named Colt that weighed 14 pounds

ColtJenn

You can learn all the details of this case, and see his surgery, by following this spleen hematoma link. Its a case study and very informative, with lots of cool pictures.

Ancillary Treatment

After surgery we will consult with the oncologists at the Veterinary Cancer Group for further treatment

Post Surgical Treatment

Prognosis

A successful outcome from surgery depends on what disease process is present and how long it has been present.

Splenic Hematoma- good

Splenic Torsion- good

Hemangiosarcoma – guarded to poor.

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Hypertension (High Blood Pressure)

Many cats are living longer lives, and unfortunately, are acquiring diseases that were not commonly seen in the recent past. Hypertension (high blood pressure) is one of these diseases. The increase in blood pressure affects many organs, particularly the liver, eyes, kidneys, and heart. Hypertension hastens the progress of these diseases and substantially predisposes your cat to blindness.We have only recently been measuring blood pressures in dogs and cats, so our database is not as complete as in humanoids. We are at the beginning stages of understanding if an elevated blood pressure is the result of a disease, a cause of a disease, or has no bearing on a disease.

High blood pressure can be primary, where the cause is unknown. In most animals though, it is secondary to some other disease.

We have a short Quicktime video on the use of our doppler blood pressure monitor. It will take a few minutes to download-you need Quicktime from www.apple.com to view it.

The are two main factors that determine blood pressure.

Cardiac output

It is the amount of blood pumped by the heart in a specific period of time. The determinants of cardiac ouptut are the heart rate (measured in beats per minute) and the stroke volume (the amount of blood in ml ejected with each beat of the heart).

Vascular resistance

This is how constricted or dilated the artery is as the blood is flowing through it. A dilated artery has a larger diameter, so less blood pressure needs to be generated by the heart for blood to flow through this dilated vessel. Arteries constantly constrict and dilate, all depending on the needs of the body overall and the specific organ they are supplying blood to. For example, the arteries to your muscles dilate when you exercise. This allows the muscles to receive extra nutrients and oxygen. When you are done exercising they start constricting and blood is diverted to other areas of the body where it might now be needed. Maybe now you are eating a meal and the digestive system needs the added blood flow.

As it turns out, is is cardiac output X vascular resistance that determines the blood pressure. If you get scared, adrenaline secretion will increase the heart rate and your blood pressure will rise due to the increased cardiac output. If you become dehydrated, the stroke volume might decrease due to a lack of fluid, and your blood pressure will decrease due to a decreased cardiac output. Older pets tend to have arteries that are not as elastic as when they were younger, the animal world version of arteriosclerosis. These blood vessels stay constricted more than dilated. This increases the vascular resistance, resulting in increased blood pressure.

Normal regulation of the blood pressure involves a complicated set of metabolic processes. Many body systems are involved, including the nervous system, the renal system, the cardiovascular system, and the endocrine system. It is a highly refined system that can make minute changes in rapid response to changing physiologic needs.

In a nut shell, the kidneys secrete a hormone called renin. This can be in response to a decreased blood flow to the kidneys, stimulation of the nervous system, secretion of hormones like adrenaline (epinephrine), or low sodium levels. Renin will activate the conversion of angoitensin I to angiotensin II in the lungs. Angiotensin II will constrict the blood vessels (increased vascular resistance) and stimulate the secretion of aldosterone. Aldosterone will increase water retention by its effects on sodium. Constriction of blood vessels (increased vascular resistance) and increased water retention (increased stroke volume) lead to an increased blood pressure. Pretty easy huh?

Pathophysiology

Abnormally high blood pressure causes blood vessel damage, particularly in the eye, kidney, heart and brain. These damaged blood vessels will bleed, cause clots, fluid buildup, and tissue death. The mechanism for this is complex.

Hypertension also places excessive strain on the cardiac (heart) muscle. The heart has to pump against more pressure (vascular resistance), causing further deterioration. As it progresses the heart enlarges and a murmur might be heard with the stethoscope.

Symptoms

There are no specific set of symptoms of high blood pressure. That’s why its called the silent killer in people. What might appear are the symptoms of the disease that is causing the high blood pressure in the first place.

The primary symptom in cats some owners notice is a sudden onset of blindness, as evidenced by dilated pupils and bumping into objects. Cats that were apparently fine just a day or two earlier are now completely blind. Prior to the onset of blindness an owner might notice other symptoms. These might include weight loss, excess drinking and urinating, vomiting, change in appetite (up or down) and fast heart rate. Monitoring some of these parameters ahead of time is possible to look for subtle signs of diseases. This is explained in our In Home Exam section and our Wellness section. 

Ollie is exhibiting all the classic signs of blindness. Both pupils are dilated and stay that way, even when a light is shined on them. In addition, his left eye shows signs of potential hemorrhage.

Cause

Feline hypertension is almost always secondary to other problems, namely hyperthyroidism and kidney failure. The majority of cats with these two diseases will eventually develop hypertension. Any cat that has been diagnosed with one or both of these diseases should be monitored for hypertension every 3-6 months.

Kidney Failure

Every beat of the heart sends a significant amount of blood to the kidneys. As cats age the kidneys do not function properly, and through complex mechanisms mentioned in the physiology section, the blood pressure will elevate.

Hyperthyroidism

The increased level of thyroid hormone (thyroxine) in the blood stream causes the heart to increase its output of blood, leading to a racing heart and an increase in blood pressure.

Diagnosis

As in people, hypertension is a silent disease. You don’t feel ill, and there are no obvious symptoms until it is too late. Fortunately, we have sophisticated medical equipment that will help us make this diagnosis.

Signalment

Found in cats and dogs. There is no breed predilection, but tends to occur more in males and older animals.

History

Older cats that have racing and pounding heart rates, along with blindness, give an indication of hypertension. Hypertension is suspected in cats that have been diagnosed with kidney or heart disease in addition to hyperthyroidism.

Physical Exam

In most cases there are no obvious physical abnormalities. Blood samples that are easily obtained, or pulsate in the syringe when obtained, are another indirect indication of hypertension. The pupils might be dilated, the thryoid gland might be enlarged, the kidneys might feel abnormal, and there could be blood in the urine (hematuria) or nose bleed (epistaxis).

An examination of the retina by an specialist will sometimes give an indication of hypertension. There might be areas of hemorrhage or even detachment of the retina. Every blind cat should be seen by an ophthalmologist to check for hypertension, along with other causes of blindness like FeLVFIP, fungal infections, and Toxoplasmosis.

Diagnostic Tests

An important tool in the diagnosis of hypertension is a blood pressure monitor. Cat arteries are very small, and the usual method to detect hypertension in people is not accurate in cats. A special blood pressure unit called a Doppler can be used. Its basis in principle is the Doppler effect (obviously). The Doppler effect is the change in frequency of a sound wave as it comes towards you then moves away from you. The best analogy of the Doppler effect is the sound a speeding race car makes as it comes towards you, then passes away from you. In the case of a Doppler blood pressure unit, it is the movement of red blood cells through the artery that is being measured. During the frequency change that occurs during this red blood cell flow the reflected sound wave goes from the ultrasonic to the audible range.

Taking a blood pressure reading on a cat is more difficult than in a person. Their arteries are very small, and of course, cats are covered with hair. Also, cats are easily stressed, which can lead to a false reading. We will routinely take several readings, discard the lowest and highest, and average the rest. Sometimes we find a cat with consistent readings each time, so not as many readings are needed. A cat with a systolic pressure over 170-180 mm Hg is considered hypertensive. In dogs we consider over 180 mm Hg to be high. Sight hounds, overweight, and older animals tend to have higher numbers. These are not hard and fast numbers, just a guideline for each individual case. In many cases of high readings we repeat the blood pressure readings later to check for consistency in the readings.

We prefer owners stay with their cat in one of our quiet exams rooms. After clipping the fur on the bottom of the rear foot (we also use the front foot and tail) we set up our equipment. We take our first pressure reading when everything is calm and all equipment is set up. Our new doppler unit has the added advantage of having head phones so that the sound of the beating artery is not disturbing to your cat.

This is an overall view of our equipment. The transducer is under our nurse’s hand at the bottom, the blue pressure-wrap is lightly around the ankle, and the pressure gauge is on the top.

This is the hi-tech part of the unit. It is a doppler transducer that allows us to detect the faint arterial blood flow to the foot

We usually inflate the pressure to over 200 or until the artery sound can no longer be heard. The pressure is slowly released until the artery sound can be heard again- this is the systolic pressure. Measurement of the diastolic pressure is not accurate by this method.

The use of the head phones is a big aid in maintaining a stress free environment. When we have obtained an adequate number of readings we can take the headphones off and allow you to listen to the artery sound with the external speaker.

Low blood pressure can be of significance in animals. Usually this is encountered during anesthesia. Our Doppler unit allows us to monitor the blood pressure during anesthesia and make corrections as needed. We also encounter low blood pressure during shock, trauma, bleeding, and from certain medications.

 

Treatment

Underlying treatment of the disease that is causing the hypertension is sometimes all that is needed to prevent hypertension. Use of K/D food, with its decreased salt (sodium chloride) might be beneficial, but this is unproven. If hypertension still persists after treating the primary problem then we sometimes will use specific medication to lower the blood pressure:

Heart Drugs

ACE inhibitors like Enalapril or Lotensin (prevent conversion of angiotensin to angiotensin II, thus decreasing stroke volume and vascular resistance)

Beta-adrenergic blockers like Propranalol or atenolol (decrease the heart rate)

Calcium channel blockers like Norvasc (decrease vascular resistance)

Diuretics

Lasix or aldactone (decrease the stroke volume)

Vasodilators

Hydralazine (decrease vascular resistance)
Blind cats need to be placed on a drug called Norvasc to rapidly lower the blood pressure. There is a chance of regaining sight with the use of this drug, especially if utilized as soon as blindness is noted. Cats that are on this drug should have their kidney tests monitored 2 weeks after starting Norvasc, then every 3 months.

The best treatment for hypertension and its associated blindness is prevention. Any cat over 8 years of age, or diagnosed with kidney disease, diabetes mellitus or hyperthyroidism, should be monitored periodically for hypertension. This will allow diagnosis of the problem before it causes blindness.

Monitoring

All pets with hypertension should have their blood pressure checked every 3 months. In addition, blood panels, thyroid tests, urinalysis, and eye exams should be performed every 3-6 months.

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