LBAH Informational Articles

Feline Immunodeficiency Virus (FIV)

The Feline Immunodeficiency Virus, also known as FIV, was discovered in California in 1986. It is transmitted from cat to cat primarily by bites and scratches, as the virus is shed in the saliva. Intimate contact through grooming, sharing food etc., does not spread the virus. This disease is found worldwide. Prevalence varies from 2.5% up to 47%, and depends on the country.

FIV is closely associated with FeLV– you should learn about both diseases if you have a cat.

FIV preferentially infects white blood cells which are an essential part of a cat’s immune system. The virus disables or destroys the white blood cells, and leaves its host susceptible to infections. Once a cat is infected with FIV it is infected for life and can transmit the virus if it bites another cat.

The prevalence of this disease has decreased significantly since it was first diagnosed. This is due to increased awareness and testing.

Even though this virus acts similar to the AIDS virus in people, humans are not infected with FIV.

Cause

FIV is caused by a retrovirus called the lentivirus. It is similar to the retrovirus that causes FeLV in cats, and causes similar symptoms, particularly supression of the immune system. It is also similar to the human AIDS virus, and is sometimes referred to as cat AIDS. There is no evidence that people can get AIDS from a cat that has FIV.

Only a small percent of cats in the U.S. are infected with this virus. One of the most prevalent methods of transmission is bite wounds in fighting cats, especially roaming males. Kittens can possibly pick up the virus in the uterus and while nursing, although most infections are in adult cats.

This virus is easily killed by routine detergents and disinfectants.

Stages

FIV has three clinical stages. The initial acute stage occurs approximately four to six weeks after infection. It may manifest as, but is not limited to, a fever, swollen lymph nodes, a low white cell count or any combination of the above. Most cats survive this phase without treatment. The second phase is a period of relative normalcy lasting months to years. The third stage of the infection results from a progressive destruction of the white blood cells and dysfunction of the immune system.

Symptoms

A variety of clinical syndromes may develop, waxing and waning for years or months until the cat succumbs. The most frequent finding is a chronic oral infection of the gums, cheeks or tongue. This infection is known as stomatitis.

When a cat is presented with gums that look like this it might have this virus and should be tested to know for certain.

Sometimes dental disease causes the gums to be inflamed. In this case, this is Grade II periodontal disease.

Cats may also acquire upper respiratory, eye, ear, or skin infections. Some cats may also show vague signs such as lethargy, fever, diarrhea, poor haircoat,weight loss or inappetance and a certain percentage may develop cancer. Diseases of internal organs like the liverkidneys, brain, lung, GI tract, and eyes are also associated with FIV due to its immunosuppressive nature.

Diagnosis

We diagnose FIV the same way we diagnose every disease, using a thorough approach.

The approach to testing for FIV is similar to that of FeLV, and follows the recommendations of the American Association of Feline Practitioners and Academy of Feline Medicine advisory Panel. Their testing recommendations are as follows:

  • The FIV status of every cat should be known
  • Yearly testing should be performed on every cat that goes outdoors or has exposure to an FIV positive cat
  • Every sick cat should be tested, regardles of previous test results
  • Every cat should be tested prior to entering a new household, whether or not they have other cats
  • When test results are negative but a recent exposure is possible (ex.-a cat that fights and has wounds). These cats should be tested at least 60 days after the last potential exposure to allow time for the cat’s immune system to develop antibodies and show up as a positive test.

Our in-house test kit that checks for the FeLV also checks for the FIV virus. It is a screening test for antibodies to the virus. If it comes back positive then a confirmation test called the Western Blot test is needed to verify the diagnosis. On occasion false positives can occur, so this verification test is important.

Kittens up to 12 weeks of age, that have circulating FIV antibodies from nursing their mothers, might also test positive. They will return to a negative state several months later, so they should be retested at 60 day intervals to make sure.

A cat that tests negative, but is exposed to an FIV positive cat, should be retested in 8 weeks.

A cat that tests positive might be a carrier, and not show any symptoms of this disease for many years, if at all.

If the test comes back negative there is minimal chance a cat has FIV. Since it takes 2-3 months (at least) for antibodies to show up in the bloodstream once a cat gets infected by a bite wound, theoretically it is possible that this is going on when a cat is tested negative. Also, in the later stages of the disease, when cats are actually showing severe symptoms, the test can be negative. This is because the immune system is so depleted at this point that it can not make adequate antibodies to fight the disease, hence there are no antibodies circulating in the bloodstream for the test to detect.

The 2 blue dots indicate a positive FIV test on our in-house test.

This same cat was postive on its Western Blot test to confirm that is has FIV. Notice the age of this cat on the top line of the form.

PCR (Polymerase Chain Reaction) test can be helpful because it tests for viral DNA, and is not dependent on antibodies from the immunes system, which can vary. In spite of this, there can be false positives and negatives, so more information and standardization among laboratories is needed before this test will be used routinely.

Treatment

There is no medication that will kill this virus. Treatment is aimed at keeping the immune system as strong as possible and utilizing medication as needed. Fortunately, the disease progresses slowly, and cats can remain healthy for several years after being positively diagnoses. FIV positive cats that are not showing any of the associated signs of illness should be examined every 6 months at least. Routine blood panels, worm checks, and urine samples should also be performed every 6 months.

Treatment of FIV revolves around the organ or organs that are most affected. This means we routinely will use antibiotics and immune simulators. Your doctor will let you know if this applies to your cat. Gum and mouth infections are treated by keeping the teeth clean and the use of oral antibiotics. As with any disease, good nutrition, routine preventive medical care, along with plenty of TLC, are mandatory for a good quality of life. There is no evidence that shows treating cats that are positive for the FIV test, but are not yet showing symptoms, is of any benefit on the health or longevity of these cats.

Since this disease suppresses the immune system in a manner similar to FeLV, therapy is similar. You can find this therapy in the FeLV page. The same caveats apply to both diseases in the use of these medications. Treatment times for both FIV and FeLV cats tends to be longer than cats that don’t have these viruses. In addition, the use of human AIDS medications have potential to help, but they have greater side effects and are considered experimental. also, their cost precludes their use in most budgets.

These cats are also susceptible to food borne bacterial and parasitic diseases due to their immunosuppression, so do not feed them raw or unpasteurized foods.

All FIV positive cats should be kept indoors to prevent transmission to other cats.

Prevention

This virus will not survive long in the environment. Still, keeping your cats environment clean, and routinely using bleach to disinfect feeding bowls etc., makes sense.

Only introduce new kittens into your household if they are healthy, free of internal or external parasites, and are current on their vaccines. The best method of preventing FIV (this also applies to the FeLV) is to prevent exposure in the first place. FIV control is aimed at preventing exposure. It is best to keep cats indoors, neuter male cats to reduce fighting and avoid introducing stray cats into a household without prior FIV testing. Also, one should segregate FIV positive cats from uninfected cats.

A vaccine was developed years ago, but it was rarely used. A major disadvantage to the vaccine is the fact that a cat that gets the vaccine will test positive on routine FIV testing for at least one year.

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Feline Urinary Tract Disease

 

Urinary bladder infections (UTI- Urinary Tract Infections or cystitis) are common in cats, especially females. As we learn more about this disease we realize many factors are involved when a cat gets a cystitis. This page will talk about some of them and how we handle this vexing problem.

This problem can progess, and it can become serious, especially in male cats. It this occurs it is sometimes called Feline Lower Urinary Tract Disease. It is sometimes also called by its previous name, Feline Urologic Syndrome (FUS). It is a disease of the urinary tract that is sometimes related to the buildup of crystals, leading to inflammation of the lining of the urinary bladder and urethra. In many cases there is no crystal buildup, so dietary changes will be unhelpful.

We have a page on bladder stones that should be read in conjunction with this page.

Graphic pictures are also present on this page as we demonstrate one of the treatments for this problem- you will be notfied when they are appearing.

A significant percentage of cats will have a UTI in their lifetime. Sometimes there are no external symptoms, but we know they have it because we find bacteria when we culture their urine. If a cat has diabetes mellitus, hyperthyroidism, or chronic renal failure, it has an 85% chance of getting  a UTI in its lifetime.

Cause

Bacteria are the cause of UTI.  A urine culture and sensitivity, obtained by cystocentesis (directly from the bladder), will let us know which bacteria are involved. By far, the most common one is E. Coli. Others include Staphylocossus and Proteus. Staph species can produce urease, which will change the pH of the urine and needs to be addressed.

The different species of bacteria are unique in how they cause this problem. Here are some of the ways they are unique:

  • How well they adhese to the urinary bladder wall with pili or fimbriae
  • If they secrete a toxin
  • If they are already resistant to an antibiotic  from this resistance being passed on from prior generations of bacteria
  • If they are resistant to an antibiotic from a recent exposure
  • If biofilms are present in the bladder

Predisposing factors

There are a multitude of factors, many of which we cannot control, and are a part of this problem:

  • The immune system of the pet in general
  • Stress in multi cat households
  • The local immune system of the lining of the urinary bladder
  • How concentrated the urine is while it resides in the bladder before urination
  • The length of the urethra
  • The strength of the urethral sphincter in preventing bacteria from going up the vulva or penis into the blader
  • How complete a pet empties its bladder (voiding)
  • Anatomical defects
  • If bladder or kidney stones are present
  • It a diabetic cat has glucose in the urine (Glucosuria)
  • Obesity and cleanliness around the external genitalia
  • Reproductive probems

Obviously, there are many factors, which is why this problem can be difficult to treat and recurrence is common.

Symptoms

In some cases there are no symptoms, and the problem is found during routine diagnostic testing. Routine symptoms include:

  • Straining to urinate
  • Blood in urine
  • Urinating frequently and in small amounts
  • Crying when urinating
  • Urinating outside the litter box

Diagnosis

Diagnosis is done with a physical exam, blood panel, urine sample, and urine culture. In some cases a radiograph and ultrasound are also used.

Treatment

Antibiotics are routinely prescribed to treat this problem. The best way to decide which one to use is with a culture and sensitivity. Antibiotic resistance is becoming more and more common, so this culture and sensitivity report is important to pick the correct one. Some bacteria are resistant to several different antibiotics. If left untreated the infection can spread from the urinary bladder to the kidneys and cause serious problems.

UrineCS

S- the bacteria is sensitive to the antibiotic

R- the bacteria is resistant to the antibiotic

In this report, the bacteria called Escherichia Coli., is only sensitive to two antibiotics.

Prevention

Access to fresh water

The proper use of a Hill’s Prescription diet to alter the urine and make it hard for bacteria to colonize

Routine urine samples and cultures to see if the problem is recurring.

FLUTD

Sometime crystal formation is a part of ths syndrome. The crystals that form in the bladder and urethra are caused by many factors, many of which are poorly understood. They include diet, urinary tract infections, and others we are not aware of. Fortunately, the dietary factors and infections can be controlled and even prevented. In a significant number of cases no cause can be determined. The name of the disease in this case is called idiopathic FLUTD. Idiopathic means that a cause cannot be identified at this time.

Two of the more common minerals that cause these crystals are struvite and calcium oxalate. Struvite is a combination of 3 minerals; magnesium, ammonium, and phosphorous. We tend to encounter this mineral combination in young adult cats. They are usually treated with diets to decrease the pH of the urine.

Calcium oxalate is the other common mineral. It tends to occur more in older cats. They are usually treated with surgical removal when found in the urinary bladder.

Diet

One of the predisposing factors in FLUTD is the magnesium (ash) content of the diet. It used to be thought that diets low in magnesium are particularly helpful in preventing the struvite crystal problem. This is not true in most cases, it is the change in urine pH from alkaline to acidic that prevents struvite crystals. In spite of this, many cat foods have restricted magnesium. Unfortunately, this diet can predispose to calcium oxalate crystals. After many years of treating cats with this low ash food we are starting to see an increase in calcium oxalate crystals for this reason. This is another example of how subtle changes in physiology, that make sense at first glance and are used successfully for many years, can have untold manifestations later.

Urine pH

It has been found that the the higher the pH (the more alkaline) the greater is the tendency for struvite crystals to form. High quality cats foods help keep the pH in the acidic range, helping to prevent struvite crystals from building up. Unfortunately, this acidic (low pH) urine now predisposes cats to calcium oxalate crystals. As a matter of fact, we are starting to see these crystals more commonly than struvite. They also tend to form with excess use of cortisone. It is important to know the pH of the urine to determine the best way to prevent buildup of crystals. For an accurate determination, the pH of your cat’s urine needs to be measured immediately when removed from the bladder. Getting a urine sample at home, and checking the pH later is not an accurate indicator of the true pH of the urine.

Infection

Urinary tract infections might predispose cats to getting this disease, although it is difficult to prove this. Even though it is rare to culture bacteria from the urine in these cats, they do respond to antibiotics. Yet many of these cats get better without antibiotics. Viruses are implicated as a cause of this disease also.

This is typical of a urine culture from these cats. After 48 hours of trying to grow a bacteria from the urine sample there was no growth. The MIC stand for Minimum Inhibitory Concentration-this is the amount of antibiotic needed to kill this bacteria, if a bacteria had been culture out. Cysto is an abbreviation for cystocentensis, the manner in which we obtain the urine from the urinary bladder.

Symptoms

Urine pH

Cats with the non obstructed form of this disease will typically be straining to urinate (stranguria), have blood in the urine (hematuria), or producing small amounts of frequent urine (pollakiuria). These symptoms can be subtle and easily missed, especially in cats that urinate outside. It is easy to confuse these symptoms with a cat that is constipated. In the male cat this problem can progress to the obstructed form of the disease, which is a medical emergency.

Other symptoms might include poor appetite, uncomfortable or in pain when petted or picked up, or lethargy.

Obstructed Form

When the quantity of crystals progresses to the point that a plug is formed then a cat becomes obstructed. This amorphous plug is not the same thing as a bladder stone. In many cats the plug that forms is made up of struvite crystals.

Cats without crystals in their urine can also get the obstructed form of the disease. This form of the disease is seen almost exclusively in male cats due to the substantially smaller diameter of their urethra. There will be repeated trips to the litter pan with straining, and crying in pain upon attempting to urinate. Again, these symptoms can be confused with constipation. Sometimes a few drops of bloody urine are produced, although many cats cannot urinate at all.

As the problem progresses these cats start vomiting, become depressed and dehydrated, and stop eating. as the problem progresses over several more hours the kidneys are unable to function and dangerously high levels of phosphorous and potassium build up in the blood stream. If not corrected, the affected cat will die from a buildup of toxins or cardiac arrest due to the high potassium.

Since all these symptoms are variable and can be quite subtle, the important point to remember is to observe your cats urinary habits on a daily basis and have your pet checked if there is any change to these habits. The symptoms of FLUTD can mimic other diseases, so an accurate diagnosis is imperative.

Diagnosis

A thorough history and physical exam go a long way towards making this diagnosis. Urine samplesblood samples, and even x-rays are used in some cases to verify the diagnosis and eliminate other diseases that can cause similar symptoms. Urine samples can be hard to obtain because these cats urinate as soon as urine fills the bladder due to the inflammation caused by the crystals. The FeLV andFIV status of all cats should be known, so these tests might be included also.

This is a picture of a cat’s abdomen. It is laying on its right side and its head is towards the left. The large, round and whitish area towards the right is the urinary bladder (B) that is distended because it cannot urinate. Compare it to the normal sized bladder below.

The normal sized bladder (B) in this cat is much smaller. In addition you can see the Large Intestines (L.I.) and the kidney (K). The small intestines (S.I.) are all the round and whitish objects at the bottom of the abdomen below the large intestines.

BlockedCatArrow

The arrow in this radiograph points to a white  area in the urethra. This is a calcified urethral plug, and makes passing a catheter difficult.

Urine samples can be useful. This one shows that there is blood in the urine an no bacteria are noted. This is typical of FLUTD.

Treatment

Unobstructed Form

Many cats will get better without any therapy at all, usually within 7 days.

For years these cats were treated with a food that acidified the urine. This food has been the gold standard for treating cats with this problem, and has helped many cats get over this disease. This acidification can be harmful though, especially in a cat with kidney disease. It can also predispose at cat to getting calcium oxalate bladder stones.

The use of antibiotics in general is not recommended because bacteria are rarely cultured in the urine in younger cats. Indiscriminate use of antibiotics in these young cats can cause the appearance of resistant bacteria. Older cats will get a urinary tract infection due to bacteria . This infection might be related to several disease syndromes, especially sugar diabetesfeline hyperthyroidism, and kidney disease.

Other medicines include cortisone to decrease inflammation and tranquilizers and antispasmodics to minimize muscle spams of the bladder and urethra. None of these medications have been definitely proven to limit the course of the disease. In addition, they all have the potential to cause side effects. Their use might be indicated as long as they do not cause more harm then good.

Oftentimes we give fluids to help flush out the urinary tract and maintain a proper state of hydration. This is a great way to help these cats, especially since there is negligible chance of problems, and we are treating them in a natural way without the use of drugs.

For cats with struvite crystals Hills c/d Multicare is the food to feed.

Obstructed Form

If not detected early and observed carefully, the unobstructed disease can rapidly progress to a full obstruction of the urinary tract, especially in males. This causes acute renal failure, and will lead to death if left untreated. We run a blood sample on these patients to determine the degree of kidney damage. Luckily, if we treat them in time the high kidney values return to normal, and the kidneys recover.

UremiaCircled

This blood sample shows severe kidney damage on a cat that cannot urinate properly because it is obstructed. The BUN and creatinine in this cat are extremely high.

UremiaCheck

After treatment the numbers started going in the right direction. This cat need to stay on IV fluids until these numbers are back to normal

Some cats have had the problem so long that their electrolytes are seriously impaired. One of the most important ones in this disease is potassium. If it is elevated significantly enough it will cause a heart problem. We can get an idea of this problem during our initial exam.

BradycardiaStethoscope

 If the potassium is high enough the heart rate will be slow, and we can detect a slow heart rate with the stethoscope to give us an idea of an impending potassium problem

Hyperkalemia1

This cat has many problem because it has been unable to urinate for several days. The high potassium is underlined. This level is not so high that it will cause a heart problem, and it is correctible with the IV fluids and normal urination

Obstructed  cats need emergency intravenous (IV) fluids and a urinary catheter placed in the urethra. The fluids are to help flush the waste products out of the bloodstream, and the catheter is to allow the cat to urinate again and remove those waste products.

Ivac

Cats with this problem will be on IV fluids for several days to hopefully return the kidneys to normal function. They are put on a special IV pump monitored by our staff.

These pets also need anesthesia for us to be able to pass the urinary catheter into the urethra and start the flow of urine again.

The following graphic pictures show such treatment.

An intravenous catheter is placed in the cephalic vein located in the front leg. It is thoroughly wrapped and will be a crucial part of the treatment. These fluids will minimize the anesthetic risk to kidneys that are already severely compromised and will also allow the flushing of the crystals out of the bladder. These fluids will re-hydrate a dehydrated cat, and also flush out excess potassium which can cause serious problems and even death.

CatIV
We use this vein because it is accessible and more comfortable than other areas

When the fluids are running and the patient is properly sedated we flush out the mucous plug. It is sometimes at the tip of the penis, sometimes it is somewhere along the urethra.

BlockedCat-MucousPlug

This large mucous plug is at the tip

In most cases, a sterile small gauge IV catheter or lacrimal canula is used to gently flush out the crystals that are lodged in the urethra. This part of the procedure can take the most time because the flushing has to be gentle, yet the crystals can be almost solid in nature.

PenisTip

A special gentle and flexible catheter is place in the urethra once we flush out the mucous plug

CatheterHematuria

When the plug is completely flushed out of the urethra the urine (usually bloody)  will immediately flow from the distended bladder

Hematuria

To make sure the bladder is empty will pull any remaining urine out with a syringe

FlushBladder

After we remove the bloody urine we usually flush the bladder to remove crystals and mucous that can cause future urethral plugs.

The urinary catheter will be hooked up to a collection bag to monitor urine output. Keeping the catheter in the urethra will let the distended bladder rest so the injured muscles can return to normal function faster.

CollectionBag

This collection system lets us quantify how much urine is being produced

When all the plumbing is flowing as it should be our patient is taken off anesthesia and brought a cage in our special cat ward to be closely monitored.
EmilyCat

After making sure his body temperature is OK Emily is transporting our patient from surgery to his private room


CatResting

To say our patient is much more comfortable now that his kidneys are able to function again, and his bladder has been decompressed, is an understatement

Most cats respond rapidly to treatment and can have their urinary catheters removed 24-48 hours later. They will remain in the hospital and be closely monitored for urinary output. On occasion they can re-block and need to have their urinary catheter replaced.

Cats that have had their bladders distended significantly before they were unblocked can have a difficult time urinating after they are unblocked. Urination is painful and the muscles that contract the bladder do not function well initially. The cats will be put on medication to minimize straining and our nursing staff will gently express the urine from their bladders when it starts to build up. If they don’t eat well we will assist feedthem. Most of these cats do well and go home in a few days. Sometimes we need owners to express the bladders at home also.

As a general rule cats with struvite crystals should be fed Prescription Diet S/D for 30 days to help dissolve crystals that remain in the urinary bladder.

Surgical Treatment

Some cats re-block continually in spite of prevention measures. Also, some cats are so severely blocked the first time that it is impossible to flush the crystals out of the urethra and place a urinary catheter to allow the flow of urine again. These cats need a surgery called a perineal urethrostomy, which in essence is a partial amputation of the penis. The penis is amputated far enough back to the point that the urethral opening is larger and there is minimal chance that a plug can accumulate and cause a blockage.

Prevention

Feeding Hill’s Feline C/D Multicare (there is even a stress version if you cat is under stress like what is found in a multi cat household).

Keeping your cat active and in good health goes a long way to preventing this problem, especially if it is obese. Keeping the litter pan clean and giving your cat access to fresh water at all times will also be helpful in prevention. The most important thing you can do is to make sure your cat is drinking adequately. The diuretic effect of adequate hydration goes a long way towards preventing this disease. If need be, give your cat supplemental water with a syringe or feed a canned food.

Cats in general maintain an acidic urine. a normal response to eating is to produce an alkaline urine initially. Medically this is called post-prandial alkalosis. If struvite crystals are implicated, this alkalosis will add to the problem. To minimize post-prandial alkalosis keep food out at all times (called ad libitum feeding).

Feeding the proper food, especially if crystals are implicated as a cause, is also an important preventive measure.

Cats that have had an episode of FLUTD should be examined by one of our doctors and have a urinalysis performed at least every 6 months.

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Hyperthyroidism

Hyperthyroidism (thyrotoxicosis) is a common hormone disease of older cats (it’s rare in dogs) that we have diagnosed with increased frequency in recent years. It is almost always caused by a benign tumor of the thyroid gland that increases the amount of thyroxine (the hormone secreted by the thyroid gland) into the bloodstream. This increase in thyroxine causes an increase in the overall metabolism of the body, leading to problems for several internal organs. Even though this disease can be diagnosed in young cats, most cats that get this problem are older. Cats 8 years of age or older should be screened for this problem when routine blood panels are run during a Wellness Exam.

Cats that have Feline Hyperthyroidism commonly have other problems that need careful attention if the thyroid problem is to be treated successfully. The excess thyroxine can cause these other problems, or make them worse if they already exist. Some of these other common problems are kidney disease,heart diseasedental diseasesugar diabetes (diabetes mellitus) and high blood pressure (hypertension) leading to blindness.

Just to show how unique each species is, dogs usually get hypothyroidism, the opposite problem with the thyroid gland.

Anatomy

The thyroid is a small and paired gland located at the neck.  It is found on each side of the trachea (windpipe). If enlarged it can sometimes be palpated. We routinely check for this enlargement during our Wellness Exam.

This picture shows the right thyroid of a dog. Note its location adjacent to the trachea (windpipe) above it.

Physiology

The thyroid gland utilized Iodine in food to produce thyroxine (also known as T-4 or levo-thyroxine), a hormone involved with the bodies metabolic rate. T-4 secreted by the thyroid gland gets converted to T-3 in the liver.  It is now called  triiodothyronine (T-3), which is the active form. When T-3 circulates through the bloodstream if affects the metabolism of every cell in the body.

Pathophysiology

The benign nodules that appear on the thyroid gland in this disease secrete excess of amounts of T3 and T4. In most cases both glands are enlarged. These hormones are not under the control of TSH (thyrotropin) secretion.

Cause

It is caused by a benign tumor (called an adenoma) of the thyroid gland in almost all cases. This tumor produces excess amounts of thyroid hormone, which circulates through be bloodstream and affects the metabolism of many internal organs. In rare cases a malignant tumor called a carcinoma is the cause.

Why these tumors occur is unknown. Several suspected but unproven implications are:

Cats kept indoors only

Cat litter

Exposure to herbicides

Fertilizers

Symptoms

The symptoms that occur depend on which internal system or systems are most influenced by the increase in thyroxine circulating throughout the bloodstream. The more common ones are:

  • Weight loss
  • Excess appetite (polyphagia)
  • Decreased appetite (anorexia)
  • Nervousness
  • Muscle weakness
  • Vomiting (emesis)
  • Diarrhea
  • Excess drinking and urinating (polyuria and polydipsia)
  • Poor hair coat
  • High heart rate (tachycardia)
  • Labored breathing (dyspnea)
  • Mild fever

It is easy to overlook some of these symptoms, especially if they are subtle. Some people even think of these symptoms as a normal part of the aging process of cats. If left untreated hyperthyroidism can cause heart failure.

Diagnosis

The symptoms of this disease mimic other common diseases in cats. These include kidney diseasediabetes mellitus (sugar diabetes), cancer, and liver disease.

Signalment

This problem occurs almost exclusively in middle aged and older cats. There is no know breed or sex disposition. Siamese and Himalayan cats are at decreased risk.

History

Cats with this problem will exhibit some of the symptoms noted above.

Physical Exam

During a physical exam some cats will appear thin, have racing heart rates, and even heart murmurs (click here if you would like to hear what a murmur sounds like). Sometimes we hear a specific type of heart beat called a gallop rhythm. Some cats even have thickened nails.

In some cats we can feel an enlarged thyroid gland. You might notice our doctors palpating your cat’s neck and throat during an exam to check for this enlargement. Some cats can have an enlarged thyroid gland that cannot be palpated because it has slipped from its normal position at the throat and repositioned itself further down the chest.

Diagnostic Tests

An important tool in the diagnosis of Feline Hyperthyroidism is a blood panel. We can sometimes detect the effects of the excess thyroid hormone on the internal organs by running a routine blood panel. This panel might show an elevation in the red and white blood cells. It is not uncommon to find elevated liver enzyme tests in cats that have hyperthyroidism. If the liver problem is secondary only to hyperthyroidism, it will usually resolve when we treat the hyperthyroidism.

Included in the blood panel is a specific thyroid test called a T4. Frequently this is all we need to make the diagnosis. Since thyroxine levels fluctuate, we occasionally need more sophisticated tests to make an accurate diagnosis.

A cat can have a normal thyroid test yet still have hyperthyroidism. This is because the thyroid hormone level fluctuates throughout the day or it might be early in the course of the disease. Also, these older cats can have other problems, which can suppress the production of the thyroid hormone. In these cats we will run a free T4 test. Lets look at a typical blood panel for a cat that has hyperthyroidism.

The arrows at the top point to the elevated liver enzymes tests in this cat. Note the arrow on the bottom pointing to the very elevated thyroid level. It is 18.3, the highest it should be is 5.2.

 

After 2 weeks of treatment the thyroid level (arrow at top) and liver enzyme levels (lower arrows) have shown a significant improvement

 

One of the most precise tests to diagnose hyperthyroidism is a scan of the thyroid gland. Not only is this test accurate in diagnosing the problem, it will also let us know if some of the abnormal thyroid tissue has repositioned itself further down the chest. An additional benefit is its ability to detect a malignant cancer of the gland in the rare occasion that this occurs.

This is the scan of a normal cat. Both lobes of the thyroid gland are visible.

 

This cat has Feline Hyperthyroidism. It is the more common benign version, and is present in only one lobe of the gland.

Treatment

There are four primary methods of treating this disease. Each has its advantages and disadvantages, and depends on your unique situation. One of our doctors will discuss which option is best used in your case.

Prescription Diet Y/D

This food from Hills limits the amount of iodine to between 0.17 ppm to 0.3 ppm (ppm is parts per million, which is obviously very little). All other cat foods have 1.5 ppm to 99 ppm of Iodine in them. It has been found that this reduction in iodine prevents the diseased thyroid gland from producing excess thyroxine. T4 levels stay normal and thus there are no symptoms. This food is made for older cats also that might have other diseases like kidney disease because it has limited phosphorous for the kidneys with extra omega -3 and omega-6 fatty acids. If your cat eats this food well this is all you need to treat the disease.

We recommend all cats that are currently on Tapazole (Methimazole) give this a try. Before changing your cat over we follow a specific protocol:

Gradually introduce the food over 7 days by mixing it in with the regular food.

Reduce the dose of Tapazole by 50% over this 7 days.

If your cat is eating the Y/D well exclusively at the end of the second week then stop Tapazole completely.

Bring your cat in for an exam and a blood panel with T4 level 4 weeks after starting Y/D. An exam is needed to check weight, listen to the heart with a stethoscope for murmurs, determine heart rate and blood pressure to make sure these problems that are common with Feline Hyperthyroidism are not present on just the Y/D food. In addition to checking the T4 level the blood panel checks for other problems common in older cats, especially the kidneys.

You cannot feed any other food, especially tuna, while your cat is on Y/D. Almost all foods contain excess amounts of Iodine, including some flavored chews, pills, and vitamins.

Radioactive Iodine

An excellend treatment that cures the disease completely in 98% of the cases involves the use of radioactive Iodine to selectively destroy only the part of the thyroid gland that has a problem. It has the advantage of a very high success rate and does not require anesthesia. It will also destroy the diseased thyroid tissue that has moved towards the chest. The disadvantage is the fact that your cat must be boarded at the treatment facility after treatment to minimize radiation exposure to others.. This treatment is done at a special center in Tustin, and is available only upon referral by one of our doctors. The center that performs the scan to make the diagnosis is the same place that will institute this treatment.

Before your pet is treated with radioactive iodine we will test its kidney function with Tapazole to determine if kidney function will be adequate after the radioactive iodine destroys the abnormal thyroid tissue. Please see our Kidney page to learn more about this.

Tapazole (Methimazole)

A relatively common treatment is the use of a drug called Tapazole. It is inexpensive and easy to give to most cats. Disadvantages are the fact that it never cures the problem, so a cat will need to be on it long term, and occasional cats get side effects to the drug. Fortunately these side effects are not commonly seen. For those cats that are hard to pill or have side effects to Tapazole we recommend Y/D or Radioactive Iodine treatment as described above.

It is used in cats that have chronic renal failure, a common problem as cats age. In these cats the excess thyroxine circulating can actually be an advantage to the kidneys because it increases the blood flow to the kidneys. This makes them more efficient at removing waste products. If we completely destroy the excess thyroid tissue with radiation or surgery, a kidney problem that was under control can now become serious. In these situations we administer a dose of Tapazole that decreases the excess thyroxine enough to make your pet feel a little better, but not so much that it will exacerbate a kidney problem that is being masked. It is a compromise in therapy because it is an attempt to balance two problems that are occurring simultaneously.

Side effects to Tapazole include facial swelling, vomiting (emesis), lack of appetite (anorexia) and depression. They can be minimized or eliminated with proper pill giving technique (the pill is bitter) or with an adjustment in dose. We will monitor thyroid levels for several weeks after instituting this therapy to arrive at the correct dose for each cat. Every 6 months we will check the thyroid level to verify we are giving the proper dose of Tapazole.

There is a topical version of Tapazole that can be formulated by one of our pharmacies. It helps minimize the inconvenience of giving an oral medication to a cat every 12 hours. The oral version is preferred, but if you cannot give your cat oral medication this is a good option. It is not as precise as the pill, and it is hard to know just how much is being absorbed through the skin. Cats on this treatment modality need to have their T 4 tests monitored more closely to make sure it is working.

There is another medication used to treat hyperthyroidism called propylthoiuracil (PTU). It has more side effects than Tapazole, so it is not commonly used.

Surgery

Surgery (thyroidectomy) is also used to treat this condition, and can be very effective. It has the advantage of a rapid and successful cure rate. Its disadvantages are the need for anesthesia and its inability to remove diseased thyroid tissue that is in the thorax. Complications could include improper calcium metabolism, hypothyroidism (too low a thyroid level), and paralysis of the throat muscles.

Tapazole is commonly used prior to surgery to minimize the symptoms associated with this disease and make the cat a better surgical candidate.

External Beam Radiation

This is for non-functional tumors. It is not commonly used.

Percutaneous Radiofrequency Ablation

Another treatment modality that is not commonly used.

Complications

If left untreated there are significant complications that can develop. Blindness can occur due to retinal detachment from high blood pressure. Long term kidney damage and non-stop diarrhea might also be consequences, along with heart failure and death.

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Intestine Tumor in a Cat

Tumors are common in cats, especially as they get older. This page describes how we treated an intestinal tumor in an 11 year old cat named Ruby. The format in this page will be different than our other disease pages. In this one we will present it as a case study, and show the diagnostic process that allowed us to make this diagnosis.

We will follow the parameters of the diagnostic process in this case, the same process we use in every diagnosis me make. If you are not familiar with this process click here  for a quick review, then come back to this page and continue the case study. You need to have an understanding of the diagnostic process in order to appreciate the thought process involved in making Ruby’s diagnosis.

This page has graphic surgical pictures.

Signalment

Our patient is an 11 year old spayed female domestic short haired cat named Ruby.

Interpretation of signalment:

Domestic short haired cats have no breed predilection, so this information does not narrow down the list of possible diseases at this point. Since Ruby is spayed there is negligible chance of a reproductive problem like pregnancy or an infected uterus, called a pyometra.

Her age is very important because it brings to mind some of the following diseases:

History

Ruby has been lethargic and not eating for 2 days. She seems painful when picked up and has been vomiting a yellow fluid. Other important parameters like bowel movements, breathing, and urination are normal.

Interpretation of history:

This information is helpful because now we start getting a feel for the extent of Ruby’s problem. It is unusual in that she is vomiting and has not eaten in 2 days, yet her bowel movements and urination are normal. A pet that has these symptoms is almost always dehydrated and would not be having normal bowel movements and urination. This discrepancy in the history is not uncommon in many cases.

Because of the new information we obtained in Ruby’s history, we need to add infection, intestinal foreign body, abscess, liver diseaseFeLVFIVFIPkidney diseasehyperthyroidism, and even poisoning to her potential disease list.

Physical Exam

  • Temperature- 104.3 degrees F
  • Weight 12.75 #
  • Eyes- normal
  • Ears- normal
  • Oral Cavity- normal
  • External Lymph Nodes- normal
  • 8-10% dehydrated
  • Heart- normal
  • Lungs- normal
  • Abdomen- 4 cm x 4 cm mass palpable in the mid abdomen
  • Muscles and Bones- normal
  • Skin- normal
  • Interpretation of exam findings:Our exam findings give us important information. Ruby has a fever (normal cats are usually less than 103 degrees F). She is dehydrated, as was expected from her history. We make a determination of her state of hydration by looking at the color of her gums, checking if her eyes appear sunken, and noting how elastic her skin is when we pull it up and let it go. The fact that she has a mass in her abdomen is one of our most important findings so far.Based on the information we have at this point we can now generate a list of Ruby’s problems:
    • anorexia (not eating)
    • Lethargy
    • Emesis (vomiting)
    • Pyrexia (fever)
    • Dehydration
    • Abdominal mass

Differential Diagnosis

This is one of the most important parts of our diagnostic process. It is a list of the most likely diseases that are causing Ruby’s problem. Based on this list we will perform specific diagnostic tests to narrow the list down to the most likely disease processes occurring. We will also institute treatment based on her problem list and the differential diagnosis. We always initiate symptomatic treatment before our test reports return. This decreases our patients’ discomfort as soon as possible, and allows us to treat the problem earlier which is always an advantage in healing.

  • Infection
  • Intestinal tumor
  • Lymph node cancer
  • Feline viral disease
  • Kidney Disease
  • Liver Disease
  • Splenic disease
  • Pancreatic disease
  • Intestinal inflammation/abscess
  • Intestinal foreign body
  • Stomach disease
  • Constipation
  • Intussusception- A disease where the intestines literally telescope into each other. This obstructs the flow of food through the intestines, and can lead to death of a section of the intestine.

Diagnostic Tests

By running diagnostic tests we rule in or rule out the diseases in our differential diagnosis list above. In Ruby’s case we initially ran a blood panel and took an x-ray.

Blood Panel

The blood panel revealed an elevation in her white blood cells. Tests of the liver, kidney, pancreas, red blood cells, protein, and viruses were all normal.

X-Ray

radiograph was taken of Ruby’s abdomen. The stomach, kidneys, large intestines, and bladder all appeared normal. The liver was slightly enlarged (called hepatomegaly). There was a large soft tissue mass effect in the center of the abdomen.

Here is a normal cat abdomen radiograph- compare it to Ruby’s below. The normal organs are identified:

L- Liver
S- Stomach
K- Kidney
LI- Large intestine
SP- Spleen
SI- Small intestine
BL- Urinary bladder
The white arrow points to sutures from a spay surgery

Here is Ruby’s radiograph. The large white section in the lower center is the problem area. This is where the small intestines (SI) are in the above radiograph. Can you see the liver, stomach, and kidneys?

A tiny needle was inserted into the mass in her abdomen and some cells were removed for analysis by a pathologist. This test is called an aspirate, and the analysis of these cells is called cytology.

Interpretation of diagnostic tests

The normal blood panel, except for the elevated white blood cell count, minimizes the chance of liver, kidney, and feline viral diseases. The x-ray eliminates constipation as a cause to Ruby’s problems. The report from the cells taken from the abdomen indicates there is infected or dying tissue in the abdomen. This is a serious finding and necessitates immediate action.

Based on these test we can now refine our differential diagnosis:

  • Ruptured intestines
  • Intestinal abscess
  • Intestinal cancer
  • Intestinal foreign body
  • Lymph node cancer
  • Pancreatitis
  • Spleen mass
  • Intussusception
  • Liver mass
  • Kidney mass
  • Lymph node mass

A determination had to be made as to the appropriate course of action for Ruby’s condition. This is based on her age, cost, convalescence, and prognosis. These important points are discussed with Ruby’s owner prior to any further treatment. The main decision for her owner at this point is to perform ultrasound versus surgery. Each has its advantages and disadvantages:

Ultrasound advantages

No anesthesia is required and Ruby does not have to undergo the trauma of surgery in her abdomen. Ultrasound is very accurate, the results of the ultrasound are immediate, and biopsies can be obtained accurately. With the ultrasound an expert can literally visualize the internal structures of an organ and make a determination on whether or not it looks healthy.

Here is a typical ultrasound picture on a different case. It is looking at the liver and gall bladder. By looking at the liver closely an experienced doctor can determine if the cells in the liver are abnormal. If they are abnormal the ultrasound is used to guide a special biopsy needle right to the problem area.

Our ultrasound doctor is giving us a demonstration of how the biopsy is obtained.

Only a small amount of tissue is obtained with this method. When analyzed microscopically by a pathologist a significant amount of information can be obtained.

Ultrasound disadvantages

Surgery might be inevitable, so why delay. No treatment can be given with ultrasound, it is for diagnostic purposes only. Delaying prolongs the time it takes to ultimately correct Ruby’s problem and adds additional costs to the bill if we do proceed with a laparotomy.

Exploratory surgery advantages

An exploratory surgery in Ruby’s abdomen is called a laparotomy. It has the advantage of giving us an immediate diagnosis and gives us an opportunity to treat the condition (if the problem is not too far gone). Also, the surgeon can literally see the internal organs in their natural color instead of grey images on an ultrasound screen.

Exploratory surgery disadvantages

It is a an invasive procedure that has risks, including the anesthetic risk. Even though the surgeon can palpate internal organs, he can not look at their internal architecture like the ultrasound does. Also, there is  post operative discomfort and convalescence when a surgery is performed. With modern anesthetics and pain medication we can do almost any surgery in an older pet and not have any problems.

In Ruby’s case a decision was made to perform a laparotomy. We were fairly certain of our diagnosis and the need for surgery, so why prolong the inevitable.

Treatment

Treatment was initiated as soon as Ruby was admitted to the hospital This treatment consisted of intravenous fluids to correct her dehydration and lethargy. She was also given intravenous antibiotics and fed a special food. Her temperature was also closely monitored. Here is a picture of part of her medical record on the day of surgery:

Status BAR means she was bright, alert, and responsive Weight- 12 # 11 ozTemperature- 103 degrees F Appetite- NPO means “nothing per os”. This is a Latin abbreviation for no food given in anticipation of surgery. Urine- NormalBowel movement- noneOur nurses noted that she had vomited during the night and she was scheduled for a laparotomy surgery sometime today. Her treatment consisted of lactated ringers solution. She was given 250 milliliters intravenously every 12 hours. Baytril, her antibiotic, was given at 1.3 milliliters intravenously every 12 hours.

Surgery

The following area contains graphic pictures of an actual surgical procedure performed at the hospital.

Ruby was anesthetized and brought into surgery when she was anesthetically stable. A 7 inch incision was made in her abdomen and her internal organs were assessed.

We suspected Ruby’s problem was with her intestines, so we immediately assessed them. The diseased area was found and brought out through the incision in her abdomen. Not only were the small intestines swollen and discolored, there was a ruptured area of infection and dead tissue. The oval mass in the picture below is a tumor in the small intestines. There is an opening in the center where it is dead and has ruptured into the abdomen.

This section had to be removed without damaging the rest of the intestines. This is a delicate procedure because the intestines have a tremendous blood supply that can easily be injured during surgery. Special clamps (seen in the picture above) are used to separate the diseased tissue from the normal intestines. Once they are in place the blood supply to the diseased part of the intestine is cut off.

In this picture the larger black arrow on the top points to the diseased intestine, while the smaller 4 arrows in the center point to metal clips that have cut off the blood supply to the disease intestine.

After cutting its blood supply the diseased tissue is removed by cutting between the 2 clamps. The clamp on the right (arrow) is on the diseased portion of the small intestine. The clamp on the left (arrow) is a very gentle clamp that keeps any intestinal fluid from spilling out of the cut end of the normal intestine. We are using the scalpel blade to make the actual cut between the 2 hemostats.

The opening of one end of the normal intestines is now visible towards the right immediately after it has been cut. The center of this opening is lined with pink tissue called the mucosa, the white area around it is called the submucosa. The submucosa is thicker than normal, indicating that there might be additional disease in this section and further intestine might need to be removed.

The tedious process of suturing the cut ends of the intestines (called an anastamosis) begins. These sutures are critical if there is to be healing and to prevent leakage of intestinal contents into the abdomen when this pet eats. The first suture is shown being placed as the process is begun.

Part way through the suturing you can see the intestines coming together nicely. The bleeding is a good sign because it is a general indication of healthy small intestine.

When all of the sutures are placed a small amount of sterile saline solution is injected into the anastamosis site to check for leakage.

This is a good overall view of the anastamosted section of intestine (see arrow). You can see how this section of small intestine is more inflamed than the normal section below it.

With the intestinal problem corrected we explore the rest of the abdomen for any other problems. Nature works in complex ways, and just because we found a problem in one area does not mean all the other abdominal organs (including more intestine) are disease free. This picture shows a normal spleen in the top left along with normal intestines on the bottom.

The diseased tissue had ruptured which means there is an infection in the abdomen (this is called peritonitis). To alleviate this infection we flush the abdomen with copious amounts of warm saline solution. This picture shows our suction apparatus removing some of the fluid that was flushed into the abdomen.

Here is Ruby just after surgery. She is a little groggy from the ordeal, but her pain medication has been administered so she is comfortable. She will be monitored closely and given some broth 12 hours after surgery. Within 24 hours after surgery she will be nibbling soft food.

A section of her surgery form describes what transpired

Her nurse was Denise Johnson and weight just prior to surgery was 12# 11 0z. The preansethetic examination by one of our doctors was within normal limits (WNL). Ruby’s preansethetic blood panel showed an increase in her white blood cells called leukocytosis. She was given isoflurane anesthetic during the procedure. Lactated ringers solution was administered during the surgery through an intravenous catheter in her cephalic vein. Immediately after surgery she was given an injection of torbugesic for pain. The surgery performed was called a laparotomy and the section of her intestine called the jejunum was submitted for histopathology by our pathologist.

Final Diagnosis

Ruby had a tumor in her small intestine called a Mast Cell Tumor. Compared to most abdominal tumors we diagnose it is a relatively rare form of tumor, and it is seen only in the cat. There is the possibility that it might spread to intestinal lymph nodes or even liver later in its course. It is difficult to say what will happen in the long term, so her prognosis is guarded.

In addition to the surgery we put Ruby on medication to minimize side effects from the tumor. Mast cell tumors have the potential to release a compound called histamine. This can cause a type of allergic reaction and even cause ulcers in the stomach lining. Ruby is on medication to counteract this problem.

Ruby returned to have her stitches removed 2 weeks after the surgery.

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Ear Mites

A common problem in cats is ear mites, especially in young cats. These mites can cause significant discomfort, fortunately most cats rapidly respond to treatment. Those that do not should be investigated for underlying problems.


Cause

Ear mites are caused by a parasite. The most common one we encounter in cats is Otodectes. It is spread by contact, and is especially prevalent in outdoor cats.


Symptoms

The primary symptoms of ear mites are scratching at the ears, shaking of the head, and a dark discharge. These symptoms mimic other ear diseases, so an accurate diagnosis is imperative.

This is typical of the discharge present in a cat with ear mites.


Diagnosis

It is important to make a correct diagnosis early in the course of the disease because it can significantly affect the final outcome. The primary method of diagnosis for this disease is a microscopic check of the discharge for mites. We look for mites or mite eggs, either one gives us a positive diagnosis.

This discharge taken from the ear of an affected cat is classic for this disease. Sometimes there is so much discharge it literally flies out of the ear as a cat shakes its head. Many people have had the lovely experience of wearing (or even tasting) this discharge as a cat flings its ears vigorously.


Treatment

Gentle ear cleaning goes a long way towards correcting this problem. These ears are very sensitive, and the ear drum (tympanic membrane) might even be damaged. Cleaning the ears of pets that might have this problem should not be attempted at home until after we have initiated therapy. We have a page devoted to ear cleaning due to its importance.

After the ears are gently cleaned by one of our nurses a topical medication is instilled. This medication contains anti-inflammatories to soothe inflamed ears, antibiotics to minimize secondary bacterial infection, and an anti-paracidicital to kill the mites. Daily cleaning of the ears and application of medication is continued until the problem is resolved, usually 7-10 days.

In some cats we use an injectable medication called Ivermectin. This drug is especially useful in cats with ears that are too sensitive to clean, or in cats that it is unlikely that you will be able to clean the ears at home on a daily basis. Ivermectin is very effective and is used commonly, although a very small percentage of cats can have a reaction to this drug and develop central nervous system signs.

The flea control product by Pfizer called “Revolution” will also kill ear mites. We recommend it as the best overall product for cats for flea and parasite control. We offer special pricing on all our dog and cat flea products that is less expensive than those advertise on TV and web site like PetMeds.

There effective ear medication for ear mites is dosed only once.

Prevention

The best method of prevention is to eliminate exposure to affected cats. Check your cats ears several times weekly and clean them as often as needed. Always clean the ear very gently to prevent trauma to a diseased ear drum. Using the flea control product Revolution by Pfizer is the best way to go to control ear mites and general parasites, including fleas.

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Feline Infectious Peritonitis (FIP)

FIP is one of the most mysterious diseases a wild or domestic cat can get. Cheetahs are particularly susceptible to this disease because of their lack of genetic diversity. FIP is a rare disease, although it is fatal. It is seen more often in cats less than 2 years of age and older than 10 years of age. Multiple cat households, along with cats that spend time outdoors, are most susceptible. The virus that causes this disease is spread by respiratory secretions and feces. Litter that is contaminated with the virus is easily trapped on a cats fur, which is ultimately swallowed when the cat grooms. Cats infected with FeLV also are more at risk of developing this disease. This disease is the subject of considerable controversy regarding diagnosis and treatment. This is partially due to the environmental situation that cats are placed in that causes undue stress on their immune systems, along with the complicated and variable immune response they develop when potentially faced with this virus. Like many cat diseases, FIP mimics other cat diseases, so a diagnosis in many cases does not come easily, especially in what is called the “dry” form. This page has short QuickTime movies on a cats with symptoms that could be the result of FIP. You need QuickTime on your computer to view it- it is available for free at www.apple.com

Cause

FIP is caused by a coronavirus, that has mutated from a harmless intestinal virus of cats called the feline enteric coronavirus (FECV). It is not known why the virus mutates from the harmless FECV (it can cause a mild intestinal upset) to the pathogenic FIP. Risk factors for this disease are multiple cat households, the presence of normal cats that shed coronavirus, age, immune status, and the development of FIP susceptible cats (including certain breeds and bloodlines) in the general cat population. The continual infection and reinfection of cats with coronavirus in multiple cat households increases the chance of an individual cat developing FIP. Any cat infected with a corona virus has the potential of developing FIP, in fact recent studies suggest up to 10% of cats infected with the corona virus may develop FIP. To give you some perspective on the current situation, 30% of household cats and up to 90% of cattery cats carry the coronavirus. Multiple cat households might be more susceptible due to increased stress, crowding, poor sanitation, parasites, and other diseases like the FeLV and the FIV. Cats can spread the coronavirus in their nasal and oral secretions, along with the feces. Even though the virus can remain infective in the environment (contaminated feeding utensils, etc.), it is easily destroyed by routine disinfectants. This virus poses no health risk for people.

Pathogenesis

Within 24 hours of ingestion the virus spreads from the tonsils to the intestines. Within 2 weeks it has spread to the large intestine, intestinal lymph nodes, and the liver. From there it can spread to any other body organ. Cats that do not produce a full antibody response to the virus will end up with fluid buildup within body cavities, usually the chest or abdomen. Cats that develop a full immune response to the virus do not get this disease, although they can harbor a latent version of the virus for a period of time. They are immune, but carry the pathogenic version of the coronavirus, so they can potentially spread it to other cats. If they become immunocompromised for some reason (stress, drugs, crowding, parasites, other disease like kidney disease ) their infection can be reactivated. This disease has two major manifestations. The first is called the “dry form”. In the dry form the white blood cells are involved, and cause an inflammatory reaction to the internal organs. These organs do not function normally because of this inflammation, and eventually will fail as the disease progresses. The dry form of FIP develops as a result of only a partial immune response to the mutated virus. The other manifestation of this disease is called the “wet form”, which is where the original name of “peritonitis” (inflammation of the lining of the abdominal cavity) came from. It is called this because fluid accumulates in the abdomen or the chest. The fluid that appears in the wet form is straw colored to yellow in appearance, and has a relatively high protein content. The fluid originates from small blood vessels that have been affected by the immune systems response to the virus. This immune response damages these blood vessels, causing them to leak fluid into the abdominal cavity usually, or thoracic cavity less often. The wet form of FIP develops as a result of a failed immune response to the mutated virus. Cats that already have FeLV are more susceptible to the FIP virus. It has been found that Persian, Abyssinian, Himalayan, Bengal, Rex, Ragdoll, and Birman cats may have an increased susceptibility to the FIP virus.

Symptoms

Initially there are no or minimal symptoms after exposure. Some cats might show mild upper respiratory signs (sneezing) or diarrhea, but are so mild that they can go unnoticed. When serious symptoms do appear, the signs might be sudden in the younger cats, or more gradual in older cats. Cats that have dry form have vague symptoms that come and go, and can affect many different systems in the body. They might be lethargic, have poor appetites,weight loss and look ill. Common organs involved are the eyes, central nervous system (brain and spinal cord), and internal organs like the liver and kidney. Other symptoms could include seizures, paralysis, behavior changes, poor vision, increased sensitivity to touch, and urinary incontinence. Another clue to dry FIP is a cat with an ongoing fever. It might wax and wane, and usually does not respond to antibiotics. Since many different organs can be involved with the dry form, the symptoms we see with this form of FIP can mimic other common diseases of cats, like hyperthyroidismliver diseasesugar diabetes andkidney disease. Other diseases like inflammatory bowel disease, cancer, and toxoplasmosis might also have similar symptoms. Pets with the wet form of the disease may have breathing difficulty or distended abdomens, in addition to some of the symptoms of the “dry form”. The onset of these symptoms is faster than the gradual symptoms noted in the dry form. The wet form of FIP is much easier to diagnose than the dry form. The virus can also infect the brain or spinal cord. This form of the disease can sometimes be diagnosed by an eye exam. Changes can be noted in the back of the eye, especially the retina.

This cat has neurologic symptoms that could be the result of FIP. Double Click on the picture to make the movie play.

Cat with Neurologic symptoms

Diagnosis

Diagnosis is difficult in many cases, particularly in the dry form. We do not have a blood test that tells us if the virus is present like we have with FeLV and FIV. The test we do have tells us if antibodies have been made to the category of virus that FIP belongs to (coronavirus), but it does not tell us if it is the actual FIP virus or not. There are DNa type tests available that are more specific in making this diagnosis, the most common one being the polymerase chain reaction (PCR) test. As we generate more data on this test in sick cats its usefulness will probably increase. In addition to specific FIP antibody or DNA tests, blood samples, X-rays and fluid analyses are also used, and are utilized especially in cats that have the wet form. The only way to be 100% certain of the diagnosis is to biopsy one of the abdominal lymph nodes, the kidneys, or the liver.

Physical Exam

Cats that have FIP will have physical exam findings similar to other feline diseases. In the wet form the fluild buildup in the abdomen or chest becomes apparent as time goes on. One of the ways we check for fluid within the abdomen during an exam is to look for a fluid wave by tapping on the abdomen. These cats will often have a persistently waxing and waning fever as well.

Blood Panel

The white blood cells might be low, normal or high, depending on how long the problem has been present and if other problems also exist. The red blood cell count might be normal or low (anemia). The biochemistry profile commonly reveals an increase in total protein and globulins. This increase is from the inflammatory process occurring as the body responds to the virus. This increase in globulins, called hyperglobulinemia, occurs more often in the dry form.

In this lab report of an FIP cat, the arrow points to the increased globulin level

Other tests on the biochemistry profile could indicate FIP, but not necessarily, since these problems could occur with other diseases also. As a case in point, if the kidney values are increased in an older cat with suspicion of FIP, some of the possibilities are:

  • Chronic renal failure along with FIP (this cat has 2 different diseases)
  • Chronic renal failure with no FIP
  • FIP causing kidney disease
  • Dehydration due to FIP
  • Dehydration due to disease in some other organ

Fluid Analysis

The fluid that builds up in the wet form of FIP is called ascites when it occurs in the abdomen, and pleural effusion when it occurs in the thorax. The fluid is sticky and usually light yellow to golden color, with a relatively large amount of protein.

This is what the fluid looks like just after is has been removed from the body.

This is the report we get from the pathologist after it has been analyzed

Radiography

The following x-rays are of a normal cat first, and then one with the wet form of FIP. approximately 100 ml (3 ounces) of fluid was removed from the chest of the cat with the fluid. After the fluid was removed it was analyzed because other diseases can cause fluid in the thorax (pleural effusion) also.

This is an x-ray of a normal cats thorax. This cat is laying on its right side, the head is towards the left. You can see the heart and the black lung tissue in the shape of a triangle. The diaphragm (arrows) is the vertical line that separates the thorax on the left from from the abdomen on the right. The liver resides in the abdomen.

This cat has a significant amount of fluid in the thorax (pleural effusion), making it difficult to identify normal organs. You cannot see the heart or diaphragm, and the lung tissue is greatly reduced because of all the fluid. The lungs are unable to expand fully causing significant difficulty in breathing. This pet is very ill and has minimal breathing reserve. It needs immediate removal of the fluid.

After some of the fluid was removed it is possible to visualize more of the organs. There is more lung tissue present and the top of the diaphragm is now visible.

The fluid found in the wet form of FIP can also occur in the abdomen (ascites). In this radiograph, the evidence of fluid accumulation is subtle, but present.

Ultrasound

Ultrasound gives us additional information on the internal organs, especially if they are surrounded by fluid.

This is what ascites looks like during an ultrasound. The dark areas, marked “abd eff” are the areas of abnormal fluid buildup in the abdomen.


The ultrasound gave us additional information we do not normally obtain from radiography. In this case, an FIP suspect, we found an enlarged lymph node (Mesenteric- LN) in the center of the intestines. This does not verify the diagnosis, but makes it very likely.

Antibody Test

Our routine blood panel in cats can also include an FIP titer. This titer detects the presence of antibodies to the corona virus, indicating exposure to the virus at some time in the past. It does not tell us if this coronavirus is FECV (the nonpathogenic corona virus) or the FIP virus. This cat might have FIP, but it might not. Also, some FIP vaccines can cause an elevated coronavirus titer. We need to see a relatively high titer, along with the routine symptoms of FIP, to make us think a cat with a high coronavirus titer indeed has FIP. To further complicate the picture, cats presented to us in the final stages of FIP, where the symptoms can mimic many other diseases, might not have any titer due to their inability to mount any immune response, hence they do not produce antibodies detectable by this test.

Here is a typical report from our lab concerning the FIP titer test. The “FCV” stands for feline coronavirus. The “IFa” stands for immunofluorescent antibody. This cat had antibodies at 1:400, but not at 1:1600. This is typical of many cats we test, and indicates at some time in the past it was exposed to coronavirus. It does not tell us if the cat has FIP or not. If the cat was positive at 1:1600 or higher, and it had all the other signs indicative of FIP, then it might indicate the cat has FIP.

DNA Test (PCR)

The DNA test for FIP is called the RT-PCR. It stands for reverse-transcriptase-polymerase chain reaction. It can be performed on blood, feces, fluid, and tissue. Not all cats with FIP have the virus in the bloodstream (called viremia), so a negative result with this test on the blood does not guarantee the cat does not have FIP. Also, the FECV (the nonpathogenic coronavirus) can sometimes be found in the bloodstream leading to a false positive. To further complicate the problem, cats with the dry form of FIP, (the very cats we run this PCR test on since we are not sure it is FIP or some other common disease causing the problem), often do not have the FIP virus circulating in the bloodstream. In this case, there will be a false negative. The test is very sensitive, so it will usually find the FIP if it is there. There is a tradeoff to this sensitivity though. It is so sensitive that if the lab does not practice a high level of quality control we might get a false positive. What this test does is look for viral nucleoprotein to the FIP virus. There is a version of this test, called the 7B protein test, which further tries to differentiate the nucleoprotein found in FIP from the nucleoprotein found in FECV.

This is what the test result for PCR looks like

Histopathology

In many FIP cases, especially the dry form, the only way to confirm the diagnosis is to biopsy an internal lymph node or internal organ, and look for specific microscopic changes that occur in FIP. This biopsy can be performed on a live cat during an exploratory surgery, or during a necropsy (the animal version of an autopsy) in a dead cat. Common organs to biopsy are the liver and kidney. In addition, the mesenteric lymph node(remember the ultrasound above where it was enlarged?) is a good organ to biopsy.

This necropsy picture shows an enlarged mesenteric lymph node. Below it you can see the inflammation that has occurred on the outer surface of the intestines. This inflammation causes peritonitis (inflammation of the lining of the abdominal cavity). This is how the disease became to be known as Feline Infectious Peritonitis when it was originally discovered.

This autopsy picture shows a reaction on the surface of the liver. This reaction is called pyogranulomatous, and is the basis for the diagnosis.

This is the final report we received from the pathologist on the above tissue samples

Treatment

There is no treatment that will cure this disease. Over the years many different treatments have been attempted to alleviate symptoms of this disease. Some of them seem to work for variable periods of time, so they are worth trying in some cases. These include antibiotics, antinflammatories, immune system stimulators, and vitamins. Since it is difficult to confirm the presence of this disease, especially in the dry form, it is worth the effort to treat your cat symptomatically. Unfortunately, the long term outcome is poor. Cats with confirmed cases of FIP usually succumb within a few months. Several antiviral medications have been tried but do not appear to alter the course of the disease. A medication called Polyprenyl Immunostimulant has shown potential experimentally for the dry form.  It has been used to treat herpes virus. More work needs to be done to make sure it works and does not cause side effects. Work on this treatment is being done by Alfred M Legendre, DVM, of the University of Tennessee. You can find these treatments in our section on FeLV, since both diseases are treating the symptoms of the virus and not the actual virus. The caveats in treating FeLV also apply to FIP.

Controlling the Spread

Cats living in households that already had a cat die of FIP have a less than 5 percent chance of developing FIP, mostly because they have already been exposed to the virus and fought it off. Siblings of cats that died of FIP have a greater chance of developing the problem due to genetic heritability for an increased susceptibility to the virus. The most important factor in controlling FIP is limiting the number of cats in a house, preferably to less than 5. In addition, good nutrition, good veterinary care, and good sanitation, will go along way to preventing this problem. Wait at least one month and preferably up to three months, before introducing a new cat to house that had a cat die of FIP. Cleaning the litter pan often and preventing litter from tracking throughout the house may be helpful. The virus can live in the environment for several weeks, so clean as thoroughly as possible using a 1:32 dilution of household bleach. Remove all cat related products that can not be thoroughly cleaned.

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Feline Leukemia Virus (FeLV)

FeLV is a serious worldwide disease of the feline world that was first diagnosed in the 1960’s. Many cats that get exposed to the virus develop antibodies and are able to fight it off. This is especially true for cats that are free of parasites, are current on their routine vaccines, and are fed a good diet. Cats that have minimal exposure to other cats are at significantly less risk of getting this disease.  Cats in households with several other cats are at greater risk. Humans and dogs do not get this disease, nor do they get FIV.

Cause

It is caused by a retrovirus (FIV is also caused by a retrovirus) that is spread from cat to cat by saliva and respiratory secretions. It is found in the urine, but this is not readily transmitted this way.

Overall infection rates range from 1% – 8% in healthy cats, up to 21% in sick cats. Younger cats are more susceptible to this virus, and resistance develops as your cat ages.

The virus does not live more than a few hours outside a cats body unless it is in a moist environment, like a water bowl. This means that cats that share litter pans and feeding bowls, along with cats that groom each other and fight, are at risk. Kittens born to mothers that have the virus are infected in the womb.


Stages

The whole process from initial infection to the shedding of the virus in body fluids takes from 2-6 weeks.

  1. The virus replicates in the lymphatic tissue in the oral cavity.
  2. If the immune system is not able to stop the problem at this stage, the virus spreads to white blood cells that circulate in the body.
  3. These white blood cells spread the virus to lymph nodes in the rest of the body. Most cats ( 60-80%) make antibodies at this stage to prevent further replication of the virus.
  4. If these antibodies are not made, the virus spreads through the circulation to the bone marrow, where it will remain for the rest of the cats life.
  5. White blood cells and platelets that are normally made in the bone marrow pick up this virus and bring it back into the circulation.
  6. The virus is spread to the salivary glands, the tear glands, and the urinary bladder. It is at this stage that the virus can be shed and infect other cats.

To summarize, several outcomes are possible if your cat is exposed to this virus:

  • It makes antibodies and fights off the virus
  • It becomes a carrier of the virus without showing any symptoms initially. These cats can spread the virus to other cats easily because they show no signs of illness. After a variable period of time these cats will probably develop one of the diseases associated with the virus.
  • The virus weakens the immune system and various problems of a chronic nature (anemia, infections, etc.) develop.
  • It causes a serious cancer of the lymph nodes, called lymphoma or lymphosarcoma. This is why it was called Feline “Leukemia” Virus when first discovered.

It is not understood why some cats can make antibodies to FeLV and never get it, while others succumb to the virus. Many factors are postulated to be involved, including stress, diet, and of course, genetics.

Symptoms

There are no specific set of symptoms that tell us for certainty that a cat has FeLV. Cats that have this virus will commonly have fevers (>103 degrees F), poor appetites, are lethargic, suffer from recurring infections, and will have experienced weight loss. Some even have skin conditions. The ability of this virus to cause immunosupression makes cats more susceptible to Demodex and Scabies.

These symptoms are quite variable though, and are also present with other diseases like hyperthyroidismliver diseasesugar diabeteskidney disease, and feline hyperthyroidism, so a correct diagnosis is important. Cats that are carriers of the disease may not have any symptoms.

An occasional cat with FeLV will have uneven pupils, called Anisocoria

Cats that have FeLV are susceptible to other diseases, notably FIA (Feline Infectious Anemia). FIA is caused by a blood parasite called Hemobartonella. This parasite will either cause anemia by itself, or worsen the anemia caused be FeLV.

Several disease syndromes are associated with this disease, especially since the virus is immunosuppressive:

Anemia can occur because the virus attacks the bone marrow and prevents the production of red blood cells. Anemia is diagnosed by a blood sample that counts the red blood cells. Pets that are anemic tend to be lethargic and have poor appetites. Cats that are anemic due to FeLV need their red blood cells checked every 3 months on a routine basis. Fortunately, this test is inexpensive and can be performed in our hospital in a few minutes. This report from our laboratory is from a cat that is very ill with FeLV. The white blood cells (WBC) and red blood cells (RBC) are very low. The low WBC helps verify that this cat indeed does have a virus that is effecting, and also warns us that this cat is susceptible to secondary bacterial infections.

Chronic wounds or infections are another common problem associated with FeLV. This occurs when the virus again attacks the bone marrow like in anemia, but this time it effects the white blood cells. White blood cells are needed to fight an infection. Symptoms of this problem could be lethargy, poor appetite, swelling, draining wounds or soreness when petted. This is a chronic non-healing infection on the front leg of a cat, typical of a cat that is immunosuppressed.

Malignant cancer of the lymph nodes occurs on occasion. This is a serious complication of the disease and requires specialized medical and surgical care. Pets with this syndrome of the FeLV virus might show signs of weight loss, have poor hair coats and poor appetites.   Our surgeon is holding an enlarged popliteal lymph node just prior to surgical removal for analysis. The popliteal lymph node is located on each of the rear legs opposite the knee.

Malignant cancers of internal organs in the abdomen. These are not usually diagnosed until they have grown significantly, verifying the importance of routine exams of FeLV positive cats.

This tumor was in the small intestines. We have a complete case study describing how we diagnose such a tumor and how we treat it.

Associated disease like FIA can occur due to immunosupression. This is a parasite of the red blood cells that can worsen the anemia that might already exist. It is treated with the use of special antibiotics, but may be difficult to control due to the effect the FeLV has on the immune system.

Diseases of internal organs like the liverkidneys, brain, lung, GI tract, and eyes are also associated with FeLV. Diseases of these organs are also treated with symptomatic care.

Testing Recommendations

Testing for FeLV is our first line of defense.

Our hospital follows the recommendations of the american association of Feline Practitioners/Academy of Feline Medicine. It has been updated several times, and this web page reflects current information.

Their recommendations are summarized as follows:

  • The FeLV status of all cats should be known
  • Testing and identifying positive cats is the mainstay of managing this disease
  • All new kittens and adult cats should be tested before introduction into any house- Kittens can be tested at any age
  • Vaccination with FeLV vaccine does not interfere with the FeLV test
  • The ELISA (Enzyme linked immunosorbant assay) test is the preferred screening test
  • All positive screening tests should be repeated
  • The IFA (Immunofluorescent antibody) test should be used to confirm a positive ELISA test
  • All cats with negative test results that are exposed to FeLV positive cats should be retested not sooner than 28 days after exposure
  • Testing of outdoor cats or those at risk for exposure to the virus should be performed annually
  • An FeLV test should be performed on every sick cat regardless of vaccine status or results of prior tests
  • Any cat in a multiple-cat household found to be FeLV positive should be isolated from other cats
  • FeLV positive cats can live a high quality life for months to years

The ability to identify FeLV positive cats has been a significant factor in the reduction of FeLV exposure and infection.


Testing Procedure

No test procedure for this disease is foolproof. Some cats can have false negatives on the test and others can have false positives. This is why all diagnostic tests are interpreted in light of other findings. This is illustrated clearly in our page on the diagnostic process.

In general, a negative test means there are no detectable virus particles in the bloodstream at the time of the test. There is no guarantee that your cat will not get this disease at some time in the future, though. A positive test should be verified, especially in cats that have no symptoms of the disease. The FeLV vaccine will not cause a positive test result.

Our in house FeLV test is the ELISa (Enzyme Linked Immunosorbant assay) test. It is the recommended test for this disease, and detects virus particles, called antigens, in the blood. It is very accurate, and checks for evidence of the virus (antigen) in blood, saliva, or tears. Most experimental cats will have a positive test 28 days after exposure, although it can be significantly longer in some cats.

One of our doctors might consider additional testing, using the PCR test,  if this test is negative. This might occur in cats that are less than 12 weeks old, or cats that have been recently exposed to the FeLF virus.

Cats that are positive on this test should be rechecked in 6-8 weeks since some of them can become negative. Or, positive cats can be checked with the IFA or PCR test, and if positive on these tests, FeLV associated disease is most likely.

This ELISA test also checks for antibodies to FIV (Feline Immunodeficiency Virus) at the same time. This added convenience minimizes cost and requires less blood than if two separate tests were run. In addition, it is highly accurate, and can be performed within 15-20 minutes.

It is a sensitive test, and can occasionally give false positive reports. Conversely, cats with a bad infection (called acute infection) can be negative on this test, when in reality there are positive for FeLV.

Specialized equipment and training is needed to accurately run the ELISA test. The bottle with the dark blue top is the reagent used to start the chemical reaction needed to read the test. A few drops of blood are all that is needed. The test kit the blood will be placed into is called a Snap test, because the right hand side of it is snapped down to complete the test.

After being placed in the reagent solution, the blood is transferred to the diagnostic test kit well. The blood immediately starts flowing towards the white circle in the center of the test kit. It takes 30-60 seconds to reach the white circle

When the blood flow reaches the center circle the kit is activated by pushing down on the elevated area on the right side of the test kit. After a few seconds the blood starts flowing back to the left.

The blood eventually flows all the way back to its starting point. After 10 minutes a blue dot appears, signifying that this cat is negative for both FeLV and FIV.

The three different type of positive results that are possible:


FeLV Positive


FeLV and FIV Positive


FIV Positive

There is an additional test for the FeLV called the IFA (Immunofluorescent Antibody) test that checks for evidence of the virus (antigen again) in white blood cells and platelets. Cats become positive on this test only after the virus has moved to the bone marrow, which takes at least 3 weeks after the virus is in the bloodstream. A positive test here means the bone marrow is infected, so FelV associated diseases which eventually appear.

This test is used to confirm a positive ELISA test, and signifies a persistent infection. It is not used as an initial screening test like the ELISA test because it can miss the initial stage of virus infection in the blood stream. This test needs to be sent to our outside laboratory, and is used only when one of our doctors feels it is necessary.

PCR ( Polymerase Chain Reaction) is another test, sent to an outside lab, that helps us with this diagnosis. It is most useful in patients that have progressive infection (they are not mounting an adequate immune response) because it detects the presence of DNA even if there is no antigen present.

To review this important aspect of controlling this diseases, current AAFP guidelines for testing are as follows:

All sick cats should be tested for FeLV, no matter what its past history, test results, or vaccine status.

All cats should be tested prior to adoption, especially if there are other cats in the household and they are FeLV negative.

All cats in a household should be tested when a new cat that is FeLV negative enters the household.

Any cat that has recent exposure to an FeLV positive cat, and all outdoor cats, should be tested.

Any cat that has an unknown FeLV status, and any cat that will be a blood donor should be tested.

Treatment

Over the year many different “concoctions” have been tried to treat FeLV (along with FIV and FIP), some with great claims of success. With the advent of the Internet these miracle cures spread rapidly, and since they are in print, somehow have great credibility. With new antiviral medications as a potential to treat viruses in the near future one day these claims may ring true. Until then, it is best to follow the treatment plan that your veterinarian recommends.

Also, any treatment has the potential to cause other problems. For example, in humans, it is very common to take megadoses of Vitamin C (ascorbic acid). Claims abound about how it cures or prevents the common cold (which is caused by a virus). Unlike people, cats can manufacture their own ascorbic acid, so it is not mandatory in the diet like it is in people. To further complicate the issue, something as seemingly harmless as large doses of this water soluble vitamin are one of the potential causes of bladder stones in animals.

There is no current medication that will kill this virus. Treatment is aimed at keeping the immune system as strong as possible and utilizing medication as needed. In reality, we are treating the symptoms of the secondary diseases that occur because of the immunosupression caused by the virus.

As in other viruses, the symptoms associated with FeLV can wax and wane, so it is usually advantageous to treat for several days to help a cat get over what is hopefully a temporary episode. Our nursing staff excel at treating cats with the significant diseases associated with FeLV, and these cats can be treated much better if they are hospitalized.

Some of the more common treatments include:

Antibiotics

Are commonly used to help these immunosuppressed cats fight off bacterial infections. The blood sample above showed a cat with a very low white blood cell count due to the virus. This cat is more susceptible to infections because of this.

If Hemobartonella (FIA- Feline Infectious Anemia) is present in the bloodstream, a special antibiotic will be used to help suppress it.

Immune Stimulators

Medication can be given that can help boost the immune system. Their effects are variable and usually are worth trying in some cases. Immunoregulin and interferon are the common medications here.

Immunoregulin is an intravenous medication made up of a killed bacteria that helps stimulate the immune system.

Cortisone

The most common form of cortisone used in cats with cancer from FeLV is prednisone. It can help reduce the size of a solid tumor (lymphosarcoma) and decrease the number of circulating cancerous cells in a cat with leukemia. Unfortunately, the mechanism that allows prednisone to cause these cancers to temporarily improved also suppresses the immune system to the point that the cat is now much more vulnerable to secondary bacterial infections.

Vitamins

These cats do not eat well and can become anemic, so supplementing with B-complex vitamins might be of some benefit. A high quality cat food should also be fed. assist feeding should be utilized in cats that are not eating anything at all.

Fluids

Cat with fevers and those not eating well will routinely become dehydrated. Giving fluids will substantially help these cats fight off some of the FeLV associated diseases. They will also help counteract the fever that commonly accompanies this virus and also when secondary bacterial infections have set in.

Red Blood Cell Stimulators

A hormone called erythropoetin can be supplemented to help minimize anemia. Unfortunately, the body might eventually makes antibodies to this oral medication and the anemia returns, sometime in a more severe form. Use of this medication requires adhering to specific protocols and close monitoring.

Blood Transfusions

These can be extremely beneficial in anemic cats that are not producing adequate RBC’s due to the virus. It must be fully understood though that this is only a temporary measure.

Appetite Stimulants

Some medications, especially a drug called Periactin (cyproheptadine) can increase the appetite in some cats.

Anabolic Steroids

These medications might help counteract anemia, increase appetite, and promote on overall feeling of well being.

TLC

A warm peaceful environment with plenty of attention are extremely beneficial.

Cats that are positive for the FeLV and are normal acting present a dilemma. These cats have a chance of dying from this virus in several years, and are the potential source of infection for other cats, yet they are perfectly normal otherwise. If the positive cat lives alone, and will not go outside, then it is reasonable to take the watch and wait approach. Much of the decision on these cats depends on the individual circumstances of your household, especially how many other cats you have. FeLV positive cats should never be allowed to roam outside. These cats should not be bred since there is a great likelihood of passing the virus to the kittens.

FeLV Vaccine

The vaccine for FeLV is effective, and all cats that go outside or are at risk should be vaccinated for this virus after testing negative on a blood sample. It should not be administered to FeLV infected cats. The vaccine will not affect the carrier state or the capacity to infect other cats. It will not reverse the deleterious effects of a cat that already has one of the diseases associated with FeLV, and it will not cause an FeLV negative cat to appear positive on testing.

Initially it is given to kittens after 9 weeks of age, and reboostered 2-4 weeks later. If the second vaccine in the 2 vaccine series is given greater than 4 weeks after the first, an additional vaccine needs to be administered 2-3 weeks later. After the initial series, yearly boosters are given. If your cat goes outside frequently, we recommend yearly FeLV testing along with vaccination.

No vaccine can be guaranteed to be 100% effective, so we recommend separating any FeLV positive cat from FeLV negatives cats, even if the negative cats are vaccinated.

Prevention

Cats that are FeLV positive should not be allowed to breed, roam or contact other cats. Keep food bowls and utensils of positive cats away from all other cats, and clean them with bleach. Replace all bedding, food bowls, litter pans etc. when bringing in a new cat to a household that has had an FeLV positive cat.

If one or more cats in a multi cat household is positive they should be removed. The remaining negative cats should be checked every 3-6 months, and if positive, be removed from the house. Do not bring a new cat (make sure it is negative of course) into a household that has a history of cats positive unless the remaining cats are negative on 2 successive tests. Wait at least one month before introducing this new cat into the household.

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Squamous Cell Carcinoma (SCC)

Squamous Cell Carcinoma (SCC) is a serious disease, but if caught early enough, there is  much we can do about it. Vigilance on your part is the key to noticing any abnormalities warranting an exam by one of our doctors. It occurs in dogs and cats, although much more often in cats.

There are two predominant versions of this disease; the skin version and the oral version.

The skin version of SCC is caused by excessive amounts of sunshine, so the disease is prevalent here in California. White haired cats have more than a 13 times greater risk of getting this disease than do cats of other colors, due to their lack of pigmentation.

The oral version of SCC is particularly aggressive as opposed to the skin version of SCC. 90% of cats with oral SCC are dead within 12 months of diagnosis. Part of this is due to the delay in diagnosis since cats hide problems and it is not easy for owners to look into their cat’s mouth.

Graphic photos later on this page.

Oral Squamous Cell Carcinoma

This is a particularly aggressive form of the disease that has unique biological behavior. It is also known as Feline Oral Squamous Cell Carcinoma (FOSCC). The oral cavity is a common site for SCC, accounting for 10% of all feline tumors. The oral version of SCC can occur anywhere in the mouth or jaw.  Under the tongue, called the sublingual area, is where it is found most often. The bone of the jaw is commonly involved, and can be readily seen on a radiograph.

Many other tumors tend to be found in the lungs when they spread to the rest of the body. This is not the case for oral SCC. If it spreads it is oftentimes found in the submandibular lymph on the same side of the mouth as the tumor.

These tumors grow rapidly and are usually well entrenched by the time a diagnosis is made. At this stage the prognosis is poor, so early detection is vital. This as another affirmation of the need for complete physical exams in cats, especially as they age. Older cats need frequent exams to catch this disease and other geriatric diseases before they have progressed too far.

The average age of cat with oral SCC is 12 years, although it has been diagnosed in cats much younger. It can occur in most any breed of cat. One year survival rate is less than 10%. Most cats succumb  to FOSCC  2-5 months after diagnosis.

Typical symptoms might include halitosis, difficulty eating (dysphagia), blood from mouth or in water bowl, and drooling. Other symptoms can be subtle and non-specific. These include weight loss, hiding, and decreased grooming.  Oral SCC can be present without any outward signs.

Is postulated that cats exposed to tobacco smoke have an increased chance of getting oral SCC. This is the same for cats wearing flea collars and those that ate canned food as opposed to dry food, especially canned tuna. It is not sure why cats eating dry food has less SCC, possibly because they might have less tartar leading to better oral hygiene. More work needs to be done in these areas to delineate a cause.

Feline-SCC1Arrow

This cat has it on its lower jaw (arrow) on the right side. The diagnosis was verified during a biopsy while its teeth were cleaned. SCC can mimic tooth root abscesses, so biopsies are recommended if we suspect it while cleaning your cat’s teeth.

Feline-SCC1-3

A closeup view shows how extensive the problem is

Fuzzer Lewis Squamous Cell of Jaw

The radiograph of this same cat shows how extensive the lesion is. There are two areas to note on this view of the lower jaw. The right jaw bone is affected. It has a moth eaten appearance that can be visualized by comparing it to the left side of the jaw.

Fuzzer Lewis Squamous Cell of Jaw

Everything within the red circle is diseased tissue. In addition to the bone lesion, the tissue of the mouth surrounding the bone is also affected. This is visualized on the radiograph as the whitish area surrounding the right jaw bone. This is the tissue that was biopsied to confirm the diagnosis. at this stage of the disease the jaw on the affected side needs to be completely removed.

 The only treatment at this point is to remove this side of the whole lower jaw. This is called a mandibulectomy. If the problem is in the tongue, chemotherapy can be used to prolong life. Radiation therapy can be used if the problem is in the upper jaw. Neither treatment is rewarding. We recommend a feeding tube in these cats to aid in their nutrition.

This surgery will be undertaken only if there is no evidence that the tumor has spread by taking an x-ray of the chest and biopsying one of the lymph nodes in the neck. It is an extensive surgery, yet most cats do fine postoperatively. If we do not remove the jaw on this side the problem will not be solved.

Complications can occur after surgery for oral SCC, although most people find them manageable. These complications include difficulty in eating. A feeding tube sometimes needs to be placed if the complications are severe enough. Minor complications might include tongue protrusion and difficulty grooming.

Skin Squamous Cell Carcinoma

In the skin version of SCC white haired cats usually get the problem on the ears, head, eyelids and tip of the nose. Cats that are not white usually develop the lesions on unpigmented areas or areas of sparse hair. It occurs mostly in older cats, but the age at which it occurs depends on each individuals’ amount of exposure to sunshine and lack of pigmentation.

Early symptoms of the disease can be subtle, such as a minor irritation or scab on the head, ears, or nose. In more involved cases there is obvious redness, irritation, scabs, and hair loss. These symptoms mimic other diseases, especially skin conditions caused by RingwormSarcoptic mange and allergies, so an accurate diagnosis is imperative.

This tiny ulceration at the tip of this cat’s nose is typical of the subtle lesion that is possible with SCC

The small red spot on this cat’s ear could also be caused from SCC

Diagnosis

It is important to make a correct diagnosis early in the course of the disease because it can significantly affect the final outcome. Diseases that can mimic the oral SCC include:

Tumors

Infections

  • Cryptococcosis
  • Blastomycosis
  • Actinomycosis

Dental Lesions

  • Periodontal disease
  • Endodontic disease
  • Benign growths
  • Polyps
  • Epulis
  • Gingival hyperplasia
  • Eosinophilic granuloma

The primary method of diagnosis for this disease is a skin or mouth biopsy. Any suspicious lesion should be biopsied since the prognosis is much more favorable the earlier the treatment. If we suspect oral SCC we might peform a biopsy or Fine Needle Aspirate (FNA) of a nearby lymph node. Many cats have lesions that are so suggestive of the disease, or the tumor is so large, that we perform surgery to completely remove the tumor at the same time we are doing a biopsy.

Lymph nodes affected with SCC can be normal in size, as opposed to lymph nodes with other cancers, especially lymphosarcoma, that can become substantially enlarged. On another note, an enlarged lymph node in a cat that has oral SCC can be negative for the tumor in the lymph node, and is enlarged for some other reason. The bottom line- a physical exam only checking the external lymph nodes by palpation is not adequate to determine spread of the oral SCC. An FNA or biopsy of the lymph node is needed.

Prior to any biopsy we need a blood panel, urine sample, and Felv/FIV tests. Some cats with bone lesions due to SCC will have a high calcium level (hypercalcemia).

Most SCC’s do not spread throughout the body, but they can recur at the site of the original lesion. Those that do spread will go to lymph nodes and the lungs. Prior to any treatment it is important to take a blood sample, a chest x-ray, and a sample of lymph node tissue for analysis. This helps stage the disease and let us know what the proper treatment regimen should be. All cats with this disease must be tested for FeLV and FIV

This is the radiograph of a dog that has cancer that has spread to its chest. The arrows point to small white areas that are the actual tumor masses that are in the thorax. They lodged here after spreading via the bloodstream from the original tumor located elsewhere in the body.

Treatment

Cats with SCC, especially the oral version, are in pain and can be in poor nutritional state. We determine this with a routine blood panel examination. Before any surgery we institute pain control and supplemental feeding, including a feeding tube if necessary.

The advent of the carbon dioxide laser in our hospital has made both of these surgeries much manageable and less painful for our patients.

Skin Squamous Cell Carcinoma is a malignant cancer that needs immediate and aggressive therapy if we hope to arrest it. The primary treatment method is surgical for the skin and oral versions. It involves removal of the affected area or partial amputation of the ear or ears. Treatment with chemotherapy or radiation are unrewarding.

If the lesion is on the nose or head a great effort is made to preserve a cosmetic look. Again, this emphasizes the need for an early diagnosis. If the lesion is on the ear then a partial amputation of the ear is performed. It is important to remove a significant amount of the ear because recurrence is common if the amputation is incomplete. The redeeming part of this surgery is the fact that most cats look great when healing is complete.

Some SCC lesions are very extensive. In a case like Ashley’s, we have to amputate almost the whole external ear due to the extensive nature of the lesion. We prefer to care for these situations long before they become this extensive.

This cat has been positively diagnosed with SCC on both of its ears, even though the problem only seems minor compared to Ashley. The small amount of redness and the minor scabs are the only apparent lesions. It is under general anesthesia, has been prepped for surgery and the amputation of both ears is about to begin.

The following pictures are from an actual partial ear amputation that we performed at our hospital. 

Since it is impossible to determine just how far the tumor has spread, wide margins are cut to minimize the potential for recurrence

The delicate suturing of the ear takes the most time in this procedure. The cosmetic appearance when healing is complete makes the time invested well worth it. Before your pet wakes up from anesthesia we will give it pain medication to minimize discomfort.

This is the appearance of the ears immediately after surgery. Within 7-10 days these sutures will be removed.

Four weeks later this is the final appearance. Many people do not even notice that any surgery has been performed. It is important to keep this cat out of the sunshine indefinitely.

We routinely perform this surgery using the carbon dioxide laser. The significant advantages are minimal bleeding during the surgery, negligible post operative pain, and no need to put sutures in for some cases.

SSC can occur in other locations and in other species besides cats

This limping dog has SCC at its toe (arrow). You can see how the bone is being destroyed.

We amputated the toe all the way up to the metacarpal joint using the laser. The arrow points out where the toe used to be. This radiograph looks different from the one above because it was take immediately after surgery and there was a bandage on the foot. This dog walked out after surgery pain free, partly because we did the surgery by laser, partly because the painful toe is gone.

Additional Treatment Regimens

Radiation therapy using Sr-90 is sometimes used on cutaneous SCC of the nose and ears.

A drug for Mast Cell Tumors (MCT) called Palladia (Toceranib phosphate) has shown some promise in survival time. Further studies are needed to see if this pans out.

NSAID’s (Non Steroidal Anti-inflammatory Drugs) like Metacam (Meloxicam) have been shown to be beneficial in post operative pain and swelling of oral squamous cell carcinoma (FOSCC). These cats eat and feel better, so they are worth it to use if needed. Care must be taken to make sure the kidneys are not in failure before use of this drug. If chronic kidney disease is present it still might be worth using Meloxicam since these cats will perish from the FOSCC problem long before the kidney problem in most cases.

A potential treatment for SCC is called Photo Dynamic Therapy. It involves the use of a laser beam to selectively destroy cancerous tissue only. An injection of photosensitive chemical is given to a pet that has SCC. The only cells that absorb this chemical are the cancerous ones. It is only these cells that are destroyed by the laser, the laser beam harmlessly passes through the normal cells that do not absorb the photosensitive chemical. If one of our doctors feels that this therapy is appropriate, they will let you know. It is considered experimental therapy, and is performed locally at the Beckman Laser Institute at the University of California at Irvine, on a referral basis only.

Prevention

The best method of prevention for skin SCC is to eliminate exposure to sunshine. The use of sun block on the tip of the nose and ears is helpful if your cat does not lick or rub it off. White haired cats should be kept indoors, and should be prevented from sunbathing for long periods of time in the window. Even though windows filter out ultraviolet radiation, they do not filter enough of the radiation in the case of SCC.

Older cats need exams at least every 6 months to aid in the early diagnosis of the other forms of SCC, especially the oral form. Careful observation of your cat’s habits as it gets older is important for FOSCC, along with many other geriatric diseases.

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Canine Fractured Tibia (shinbone)

Some fractures are so severe they require the expertise of a specialist in bone surgery. We have a specialist in bone surgery that will come to our hospital and perform the repair. This has several advantages, not the least of which it costs less than if we refer the repair to a surgical specialist at his hospital. These pictures show the repair of Dakota, a Labrador who fractured his tibia (shinbone) by playing.

Type of Fracture

This fracture is called a spiral fracture due to the winding nature of the crack. The fracture is much more severe than is apparent on this x-ray. What is not apparent on the x-ray are the numerous bone fragments that were found surgically.

Surgery

The following area contains graphic pictures of an actual surgical procedure performed at the hospital. It may not be suitable for some children (and some adults also!). Click here if you would like to bypass the surgery pictures and view post operative x-rays.

Our surgeon needs to utilize specialized equipment if he is to put this bone back together so that Dakota can return to normal function. In this picture he is using magnifying glasses and special lighting. In addition, he has orthopedic instruments and equipment without which he would never be able to repair such a severe fracture.

Bone infections can be serious so significant time is spent in sterile preparation. When Dakota has been anesthetized, and adequately prepared, an incision is made on the inside of his leg. This area has minimal muscle over it and gives good exposure to the fracture site.

After careful dissection and control of hemorrhage the main fracture segments are isolated.The surgeon uses special wires called cerclage wires to begin the process of holding the fracture segments in place. It is a tedious process that takes up a significant amount of the surgery.

The wire is tightened down with a special instrument that gives just the right amount of tension. Too little tension and the wire is useless, too much and the bone fractures even more.

At this point 2 cerclage wires have been applied to the fractures at the top, with new ones being applied to the fractures at the bottom

 

Eventually 6 cerclage wires are applied to align the bone fragments. Even though these wires are strong the bone will not stay in place and heal with just these wires. A bone plate is needed for most of the stability.

After the bone plate is measured and bent to the specific shape of this tibia, holes are drilled into the bone with a special air powered drill. They have to be drilled to the proper depth and angle or the bone will fracture more or the plate will fail.

 

Drilling the holes is the first step in the application of the plate. The depth of the holes is measured, and specific screws are used. Some screws compress the plate to the bone, others hold the plate in place.

Two hours from the start of the surgery the plate has finally been applied. We will not remove it unless there is a post operative complication.

The muscle is sutured to preserve its function and to cover the plate. These sutures will slowly dissolve over several months.

The skin sutures will stay in for 2 weeks. at this point in the surgery Dakota is given an antibiotic injection along with a pain injection. after one nights rest in the hospital he will go home. He will need to be confined for one month for healing to progress.

Before Dakota is fully awake from anesthesia an x-ray is taken to assess the surgery. The bend to the plate can be seen, along with the cerclage wires and the different lengths of the various screws. The fractured fibula (arrow) will heal by itself.

Once our surgeon is satisfied that everything is in order Dakota is given a pain injectionand awakened from anesthesia. He will spend the night with us so that he can rest and so we can monitor his recovery. He will need to rest at home for several months before the healing is complete. We will not take the plate out unless complications arise.

One month after the surgery we took an x-ray to make sure the plate is holding well and the bone is healing. If you look carefully, the small bone in the leg, called the fibula, is healed (arrow). Compare it to the x-ray above where you can see the fractured fibula.

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Mast Cell Tumor

Up to 20% of dogs will get a malignant Mast Cell Tumor (MCT) in their lifetime, making it the most common tumor we encounter in dogs. Other names for MCT are mast cell sarcoma, histiocytic mastocytoma, and mastocytosis.

This disease has a cutaneous form (skin) and a systemic form (internal organs).  The cutaneous form is more prevalent, and is sometimes referred to as the “great pretender” because the skin growth appearance is so variable.  What might seem like just a minor swelling or inflamed area can be a highly malignant cancer. It might also be called the “great fooler” because most people underestimate the problem.

MCTs have the potential to be highly malignant and their treatment needs to be thorough and comprehensive in order to minimize the chance of spread and premature death of your pet. In almost every case the treatment of choice is surgery to remove the tumor. After surgery additional treatment might be indicated.

This page will give detailed information on MCT in the dog since that is the primary species that gets this disease. We occasionally see MCT in cats and ferrets. MCT are second most common tumor in cats. They behave somewhat differently in our feline friends. We will go over MCT in the cat at the end of this page.

Throughout this page are links to numerous other areas on the LBAH web site to give you additional information on that specific topic.

There are some mild surgery pictures in this page showing the open skin after a MCT has been removed. They are suitable for most viewers.

Physiology

Mast cells, also known as mastocytes, originate in the bone marrow and live for weeks to months. Once produced by the bone marrow they circulate through the body ending up in large numbers in the connective tissue of the body, lymph nodes, under the skin, and in internal organs.

Mast cells surround nerves and blood vessels, and are oftentimes found at the interface between the environment and the pet. This means they tend to be found in higher numbers under the skin and the lining of the respiratory system and digestive systems. They play a role in wound healing and defense against invading bacteria, and are a big part of the immune system. They have binding sites on them for the immunoglobulin called IgE. This immunoglobulin is a big part of the immune system when it comes to allergies. You can learn more about it by linking to our allergy page.

Mast cells have the potential to release several different compounds, the most important of which are called vasoactive amines. Vasoactive amines are nitrogen-containing compounds that act on blood vessels. The more important vasoactive amines are histamine, heparin, serotonin and prostaglandin. Histamine is the most important one in relation to MCT.

Histamine goes to the stomach lining and stimulates the secretion of gastric acid. Histamine also dilates blood vessels and increases permeability of the blood vessels, leading to swelling (edema). This mechanism is part of the normal inflammatory process.

Release of large amounts of histamine from a mast cell can result in ulceration or perforation of the GI tract (stomach and intestines) causing pain, hemorrhage, delayed wound healing, shock, and dark blood in the stool (melena). A significant number of dogs with MCT that are necropsied (autopsied) after death have ulcerations in the stomach.

This release of excess histamine is called the paraneoplastic syndrome. It is serious and needs to be addressed prior to and after treatment. This is why any skin growth needs to be handled gently in case it is a MCT and histamine gets released in an excessive amount.

When excess secretion of histamine occurs and only affects the skin it is sometimes known as Darier’s sign. You will notice raised and red areas of the skin when this happens.

In young animals the disease might spontaneously resolve. This is not something you should count on though. This cancer in dogs is unpredictable and can be extremely aggressive, so waiting to see if it resolves is not a good option. Every MCT should be treated as potentially malignant. MCTs can mimic other tumors, making it impossible to identify them simply by appearance.

 Tumor Behavior

As a general rule, benign MCT will be slow growing, well circumscribed (their margins are easy to feel), non-painful, not attached to the underlying tissue, and exhibit minimal inflammation. They might be irritated if your dog or cat is licking at them.

Malignant tumors tend to grow more rapidly, might be ulcerated or painful, have poor margins to determine where they begin and end, are fixed to the tissue below, and may have spread to nearby blood vessels and lymphatic tissue as evidenced by enlarged peripheral lymph nodes.

If the MCT spreads to the internal organs (called systemic mastocytosis) it usually goes to the liver, spleen, lymph nodes, or even back to the bone marrow.

In dogs most MCT are usually found on the trunk and perineum, sometimes on the limbs, and occasionally on the head or neck. MCT of the perineal and inguinal regions tend to behave more aggressively than their tumor grade would predict. Some dogs get multiple tumors.

Mast cell tumors that are large (more than 4 cm), on the face, muzzle, and oral cavity tend to have a poor prognosis.

Mast cell tumors located in the perineal region (anus, scrotum and vulva) may be may be more difficult to remove completely. They might need additional surgery or radiation and chemotherapy.

Dogs that have signs of gastrointestinal ulcers (vomiting, poor appetite, lethargy, or black stools) generally have a poor prognosis. Tumors that recur soon after surgery have a poor prognosis.

You cannot tell definitively whether any skin inflammation is a tumor or something else, and if it is a tumor, whether it is benign or malignant, just by looking at it or feeling it. Microscopic analysis by a veterinary pathologist is the only way to confirm this diagnosis. When we take a tiny sample of cells with a needle (called a fine needle aspirate- FNA) we call this cytology. When we take a large piece of tumor, or even the whole tumor, we call this histopathology.

Cause

There are several factors that contribute to this problem that include genetics, hormonal, environmental, and immune influences. There is suggestion that MCT are related to red or golden hair coats, allergies, or viruses. None of this has been proven at this time.

As is the case with many cancers it is a genetic mutation that is the originating factor. A tumor suppressant gene (called p53) can mutate and is suspected to cause MCT in 50% of the canine cases.

A gene named C-Kit can mutate, leading to excess production of a protein called Kit, which can cause excessive stimulation of mast cells.

Diagnosis

Diagnosis is made based on the Diagnostic Process we utilize in call cases. This includes:

  • Signalment- species, breed, reproductive status, and age.
  • History- observations of the problem you make at home, along with diet, environment, medication, and past medical history
  • Physical exam- Abnormal and normal findings on our exam
  • Diagnostic tests- used to rule in our rule out certain diseases
  • Response to treatment- Does your pet improve when we treat it

For more detailed information on the Diagnostic Process follow this link .

1. Signalment

MCT’s occur in both males and females, typically around 8 years of age or older, although they have been seen in dogs much younger.

This is one of the few diseases that might occur in mixed breed dogs as much as purebred dogs. Certain breeds have a higher incidence though:

  • Boxers
  • Pugs
  • Boston Terriers
  • Labrador Retrievers
  • Beagles
  • Schnauzers
  • Bulldogs
  • Bull terriers
  • Basset hounds
  • Weimaraner
  • Golden retrievers
  • German shorthaired pointers
  • Scottish terriers
  • Shar peis
  • Rhodesian ridgebacks

In cats it is the Siamese breed that has a higher incidence. There is no difference in occurrence rates between males and females.

 2. History

The most consistent symptom of pets with MCT is a growth somewhere on the skin when grooming or petting. Multiple growths are possible, but in most cases it is one skin growth that is found. It might be tiny and barely inflamed, or it might be large and firm. Some pets will be oblivious to the tumor, while others might lick or chew at it. Many MCT wax and wane, which can make pet owner’s think the growth is not important. This waxing and waning can go on for months.

Other symptoms depend on whether heparin or histamine is being released (the paraneoplastic syndrome). In this case a pet can be vomiting, have a bleeding disorder (coagulopathy), have stomach ulcers, blood in the stool (melena), poor appetite (anorexia) or no appetite, abdominal pain, or literally be in shock.  Some symptoms will look as if your pet is having an allergic reaction and require immediate veterinary care. In pets that have spread of MCT to other parts of the body there might also be weight loss.

The following pictures are all MCT’s. As you will see they can vary considerably, so just looking at a skin tumor will not give you a diagnosis. Basal cell tumors, histiocytomas, soft tissue sacromas, and lipomas can all look like mast cells at times.

 This is a close up of a 2.5 cm mast cell on a dog’s side

This large mast cell is on the back of a dog’s leg seen as it is being prepped for surgery

Above the vulva

A large MCT on a dog’s upper eyelid. To help you get your orientation this is the left eye and the dog is facing to the left.

For curiousity sake this is the same dog immediately after surgery

On the skin of the rear leg

Another close up of a MCT on the side

The white arrows are pointing at a MCT on a dog’s scrotum

The black arrow points to an almost imperceptible area that is slightly red and raised. This is a MCT

3. Physical Exam

A complete physical exam is performed on every pet brought to us for a skin growth. There are a multitude of reasons why check other body organs and not just the skin growth you noticed at home:

  • So we do not miss other skin growths that might also be present and that are small or hard to detect. These might be other MCT, lipomas, or squamous cell carcinomas, for example.
  • To ascertain any spread of tumor to lymph nodes. We check the following peripheral lymph nodes during our exam:

o   Submandibular

o   Pre-scapular

o   Axillary

o   Inguinal

o   Popliteal

For more information on where these lymph nodes are located and their role in the immune system follow this link. Our doctors will gladly show you how to palpate them for an in-home exam.

  • To look for other problems that might be present but not obvious. Common ancillary problems in pets that get MST include dental diseasearthritiskidney diseaseliver diseaseheart disease (a heart murmur might be detected), skin allergies and even obesity. It is important that we address these issues for a successful outcome when treating MST.
  • To make sure the pet is ready for any anesthesia in the future

Care must be taken not to palpate a suspected tumor too vigorously because if it is a MCT it can degranulate and release histamine.  At the least it might cause the skin growth to become more inflamed (Darier’s sign), and in the worst case it will cause your pet to go into an allergic reaction and shock if excess histamine is released from the MCT. This is a rare occurrence but something to keep in mind as you touch any specific growth on your pet’s skin.

4. Diagnostic Tests

Routine blood panel, urinalysis, and fecal exam are needed in every case prior to any treatment. These tests give us a detailed picture of your pets overall health status and look for other problems that are not obvious during the physical exam. Finding other problems in pets that present for just a skin growth is a situation we encounter more often than you might think. Heartworm and FeLV/FIV status needs to be know also.

The results of a normal blood panel on a dog that prior to mast cell tumor removal. Sometimes we will see anemia due to blood loss from an ulcer in the GI tract.  We might also see an increase in liver enzymes if the MCT has spread to the liver, and also an increased BUN (Blood Urea Nitrogen) if there is GI bleeding.

We take special pre-anesthetic precautions on older dogs undergoing mast cell surgery. One of those precautions is an EKG to make sure the heart is ready for anesthesia. This is the same dog as the blood panel above, and is a normal EKG.

A very important test to diagnose any skin tumor is called a final needle aspirate (FNA). In this test we take a tiny needle and syringe and obtain some cells from the mass. The test is easy to perform, feels like a pinprick, and does not require anesthesia. It is similar to giving a vaccine, but in this case we are not giving something, we are taking something.

The small number of cells obtained from an FNA are put on a microscope slide and sent to our pathologist. They know why we are sending the sample to them and they specifically look for any signs of a benign or malignant tumor. Due to the high incidence of MST they look for these cells specifically. Pathologists are experts at analyzing cells under a microscope and they will come to one of the following conclusions:

  • They will tell us what cells the aspirate is made of and recommend appropriate treatment.
  • They will give us an idea of what different cells might be involved but have no specific diagnosis
  • They will not be able to tell us anything because of too few cells in the sample or the cells are not identifiable.

This is what a pathologist is looking for under the microscope for a FNA. The arrow points to a clump of 3 mast cells that have been stained to stand out.

Here is a typical report from a FNA on a dog with MCT

Even though no guarantee can be given to the usefulness of the FNA, it is worthwhile in almost all cases because the potential to give us useful information is high, especially when you consider the ease of obtaining the sample.

Knowing whether we are dealing with a MCT ahead of surgery is important because these tumors need aggressive surgery to be certain we remove the complete tumor. If we know going into surgery that we have a MCT we will take at least 3 cm margins around the visible mass. We will also dissect down to a deeper fascial plane to make sure no tumor remains after surgery. This type of aggressive approach is usually not needed in other skin tumor surgeries.

A pre-surgical radiograph is indicated in many cases to look at the thorax and abdomen looking for any spread of the MCT from the skin to the internal organs (systemic mastocytosis).  In addition, a radiograph is indicated any time we anticipate anesthesia and surgery.

We might seen an enlarged sternal lymph node in the chest if the MCT has spread.  The white arrow points to the location where the sternal lymph node resides.

This crescent shaped organ under the black arrow is a big liver, called hepatomegaly, on a radiograph. A MCT is one of several causes to an enlarged liver.

This is a large spleen, called splenomegaly, on a radiograph.

If an abnormality is found on the physical exam, or any diagnostic test, an ultrasound might also be needed. If we see an enlarged liver or spleen prior to surgery we will perform an ultrasound. This is what a spleen looks like during ultrasound

Here is the report on the normal appearing dog spleen above. There is no sign the MCT has spread to the liver or spleen.

DESCRIPTION:

Cellular slides consist of a heterogenous lymphoid population and a few scattered aggregates of stromal connective tissue/splenic trabeculae against a hemodiluted background. Small mature lymphocytes predominate followed by a low number of intermediate lymphocytes and large lymphoblasts. A few metarubricytes, mature plasma cells, and macrophages noted. Nor organisms or atypical cells seen.

MICROSCOPIC FINDINGS:

Spleen consistent with normal or hyperplastic lymphoid tissue

This is an enlarged spleen with nodules that could be caused by a MCT, although there are other causes to this also

If a regional lymph node is enlarged or draining we will perform an aspirate to determine if the tumor has spread. We can also aspirate the bone marrow looking for mast cells.

Information from all these tests is used as part of the surgical plan. It is also used to determine prognosis after surgery once the final tissue sample has been analyzed. If it looks like there has been the spread of tumor to an internal organ then chemotherapy or radiation therapy might be indicated in addition to surgical removal of the mass.

Surgical Treatment (surgery pictures in this section)

The overwhelming majority of MCT are treated with surgery. Microscopic tumor cells that are not visible or palpable can occur, so we remove a margin of 3 cm from the edge of the visible or palpable tumor. We also dissect deep down into the tissue for another 3 cm. This is problematic on tumors of the face, neck, and extremities. In those cases radiation and chemotherapy might be more appropriate.

It is not unusual to perform more than one surgery, especially if the tissue report (histopathology) reveals that we did not remove all of the tumor. This is referred to in the report as the margins not being clean. We like to have 10 mm margins to feel comfortable that we removed all of the tumor. When in doubt a second surgery is indicated to remove any suspected tumor remnant.

We use the laser for all of our MCT surgeries because of the dramatic reduction in bleeding during surgery, along with substantial reduction in swelling and pain after surgery. In the picture our surgeon is gently holding the mast cell between his fingers as he dissects with the surgical laser.

The tumor has been completely removed (notice the lack of bleeding) and what you are seeing is the fat layer under the skin. Notice how large the incision is. This is because we took 3 cm margins on all sides of the tumor, and also because the skin is under tension and spreads wide open when we remove the tumor.

In most cases we need to go deeper than this fat layer and get right down to the muscle layer. At this point we feel comfortable that we have gone 3cm deep into the tissue and have removed all of the tumor that is not visible or palpable.

The piece of sking with the MCT in the center after removal

 

MCT surgical sites sometimes heal poorly due to the disruption the cancer cells cause in the area. This fact, added to such a large incision, has the potential to heal poorly due to the tension on the skin. It is imperative that your pet wears an e-collar and you follow our postoperative instructions.

During the surgery we might also perform an aspirate or biopsy a lymph node in the region of the skin mass to look for spread of the tumor.

Gentle tissue handling is important when obtaining a fine needle aspirate and during the actual surgical procedure. Mast cells can release histamine during these times, so in addition to gentle handling we might put your pet on prednisone, Benadryl, and Pepcid AC prior to, during, and after surgery to minimize the release of histamine and its serious effects on the stomach and intestines.

In the rare cases where surgery might not be feasible, or the tumor is not completely removed, treatment can include medical therapy, radiation therapy, and chemotherapy.

Tissue Analysis and Prognosis

Analyzing the removed tumor tissue after surgery, called histopathology, is crucial to confirm the diagnosis, determine if more surgery or treatment might be needed, and to make a long term plan. The pathologist will let us know if the entire tumor was removed, what grade the tumor is, and what is the mitotic index of the tumor. This is a typical report on a dog with MCT:

SOURCE– 5 cm skin biopsy of mass on left flank

DESCRIPTION

 Examined is a section of skin and subcutis. The section contains a moderately well-dilineated, loosely cellular, unencapsulated dermal and subcutaneous neoplasm. Neoplastic cells are generally round and characterized by round to oval nuclei with moderate variation in nuclear size and chromatin pattern, and moderate to abundant amount of pale amphophilic to deeply basophilic granular cytoplasm. These cells infiltrate between resident collagen fibers, and are accompanied by low numbers of mature eosinophils. The mitotic index is 1. There is multifocal collagenolysis and eosinophil degranulation throughout the mass.

MICROSCOPIC FINDINGS–  Grade 2 mast cell tumor, well-differentiated, mitotic index 1.

PROGNOSIS– Fair to guarded

COMMENTS-Local excision appears to be complete with margins of 1.3 and 1.0 cm on either side, and 0.4 cm deep. Within the sample submitted there is at least one fascial plane deep to the tumor.

Grade 1 MCT are what is called well-differentiated and are usually benign. Grade I MCT occur in 30% – 50% of dogs.  Up to 90% of dogs are cured by surgery alone.

Grade 2 MCT are intermediately-differentiated and might be benign or malignant. In other words, they are unpredictable. Grade II MCT occur in 25% – 55% of dogs. Mean survival time after surgery is 28 weeks. Radiation therapy following incomplete removal can cure over 80%. Chemotherapy is sometimes used in addition to radiation therapy.

Since these tumors can go either way more information is helpful to determine the next course of therapy if at all. This is where the mitotic index comes in to play.

Grade 3 MCT are poorly differentiated and usually malignant. Grade III MCT occur in 20% – 40% of dogs. Mean survival is 18 weeks with surgery. Post-operative chemotherapy and/or radiation therapy might prolong survival.

Mitotic index is another predictor of biological behavior of MCT. Mitotic Index is an indirect measure of cell division. It is measured as the number of mitotic figures per 10 high-powered fields (a high powered field is 400x) when using a microscope.

These grading systems are the best way to determine the individual behavior of the MCT we remove from your pet and its prognosis. Nature is complicated, and unfortunately, not all MCT fit into these orderly classifications, so thoroughness of treatment and vigilance for recurrence are important.

In addition, histopathology is an art and a science, so a pathologist that might assign a specific grade to a tissue sample might not be consistent with another pathologist. Because of this no guarantee can be given to any of these prognostic indicators.

Different studies give varying statistics on prognosis. According to the Veterinary Cancer Group in Tustin, CA the prognosis is as follows:

Grade 1 tumors have a 5-67% chance of recurrence at 12 months.

Grade 2 tumors have a 50% chance of recurrence at 10 months. 88% of dogs with Grade 2 tumors that are incompletely excised and undergo radiation are disease free at 5 years.

Grade 3 tumors have a 94% chance of recurrence at 12 months.

Dogs with a mitotic index of 5 or less had an average survival time after surgery of over 70 months. Those with a mitotic index of greater than 5 had a survival time of less than 2 months, no matter what grade of tumor it is.

Another study showed that 83 percent of dogs with a Grade I MCT, 44 percent of dogs with Grade II and 6 percent of dogs with Grade III were living 1500 days after surgery.

In another study, 100 percent of dogs with a Grade I MCT, 44 percent of dogs with Grade II and 7 percent of dogs with Grade III were living two years after surgery.

Radiation and chemotherapy may be used following surgery. Even if the MCT is not completely removed, 90 percent of dogs that received radiation following surgery for Grades I and II MCTs survived for at least three years.

Medical Treatment

Medical treatment is usually used when surgery is not feasible. Prednisone, a very common and effective corticosteroid (cortisone), can help in some cases when used judiciously and monitored for side effects.

Chemotherapeutic drugs are sometimes used in dogs, especially if the tumor has spread. Common drugs include:

  • Lomustine
  • Masitinib
  • Palladia
  • Vinblastine
  • Torcerinib

Palladia is a kinase inhibitor which blocks the excessive production of the kit protein. It is FDA approved to treat MCT in dogs and is getting lots of hype. It is not a panacea, and when it does work (around 40% of the time), the response is for around 3 months.

Use of chemotherapeutics should never be undertaken without consultation with a veterinary oncologist. These drugs are powerful and need to be monitored for potential side effects. They also cost more than the other medications we routinely use.

Additional Therapy

As is the case with every disease, proper nutrition, access to fresh water at all times, parasite control (both external parasites like fleas and internal parasites like roundworms), exercise, and lots of TLC cannot be overlooked. In our older pets particular attention needs to be paid to the debilitating effects of arthritis, dental disease, and chronic organ disease. Hill’s makes a Prescription Diet for cancer patients called n/d that nourishes the patient without nourishing the cancer cells.

Long Term Care

Even if we completely remove a MCT there is up to a 17% chance another one will appear during your dog’s lifetime. Vigilance and early detection is of importance. Run your hands over your dog’s body at least several times per week for any problems. If you find any mass or growth we need to do an immediate FNA (Fine Needle Aspirate) looking for mast cells. We will teach you how to palpate the more obvious external lymph nodes as an additional monitoring technique.

Any pet that has been previously diagnosed with a MCT should be examined every 3-6 months. This exam should also include a blood panel, urinalysis, fecal exam, radiograph, and abdominal ultrasound.

Feline Mast Cell Tumor

MCT are the second most common tumor in the cat. Even though the basics are the same, MCT’s in cats behave differently than dogs. Cats get a skin form (called cutaneous) and what is called a visceral form (internal). It is possible for a cat to get both forms. They tend to get systemic mastocytosis more commonly than dogs.

There is no correlation to FeLV or FIP in cats that develop MCT. Siamese cats might be genetically predisposed because of a greater occurrence in this breed.

In the cat the grading system used for dogs does not apply regarding prognosis. Some are benign and some are malignant, and spread of the tumor (metastasis) can occur.

Cutaneous Form

The skin form of the feline MCT occurs around the head, eyelids and neck. Lesions can look like almost any growth, although they tend to be solitary, hairless, and raised. Lesions could be multiple, although the presence of multiple lesions does not necessarily mean a poor prognosis. Cutaneous MCT in the feline is usually benign, and for the rare times it does spread, it will go to regional lymph nodes, liver, spleen, and bone marrow just like in the dog.

Visceral Form

The visceral from of MCT usually occurs in the spleen first, then less commonly in the liver or intestine. MCT is the 3rd most common intestinal tumor in the cat after lymphoma and adenocarcinoma.

Typical symptoms in a cat with visceral MCT are vomiting, poor appetite, lethargy, and weight loss. These are the same as the dog and relate back to histamine release in excess.

During a physical exam one of our doctors might palpate an enlarged liver or spleen, abdominal fluid (ascites) or even a mass.

Treatment

Treatment of choice in both forms is surgical removal. If the pathologist report says tumor margins are not clean we can perform the surgery again or do radiation therapy.

The spleen is a common organ for visceral MCT in the cat. This is a normal spleen during surgery.

Prognosis

Prognosis of mast cell tumors of the skin is usually excellent and surgery is generally curative.

Prognosis of mast cell tumors localized to the spleen is good and many live for an additional one to two years after the spleen is removed.

Prognosis is guarded if the mast cell tumor is located in the gastrointestinal tract.

A good prognostic indicator in the cat is appetite when first examined. Those eating well tend to live much longer.

We have a case study of a cat (her name is Ruby) that had intestinal mast cell tumor. The case study covers this cat’s diagnosis and treatment from beginning to end, with pictures of surgery. Here is the link.

Cancer Specialists

When we treat a case of MCT (or any malignant tumor) we routinely refer the case to the Veterinary Cancer Group. They are experts on cancer in animals and provide the latest treatment available. Any time we diagnose and treat a dog or cat with MCT (or any malignant tumor) we recommend you go to them for a second opinion. They will review all data and set up a long-term plan. They are also able to provide chemotherapy and radiation therapy.

This email was sent to us through the LBAH email system. It is typical of the feedback we receive from clients sent to the Veterinary Cancer Group.

Below is the result of your feedback form.  It was submitted

on Thursday, August 11, 2011 at 10:25:07

Name: Leslie

location: Anaheim, CA

Dear Long Beach Animal Hospital,

I just wanted to thank you for everything you’ve done for Bijou and me over the years.  There are no words to express my gratitude to you and your staff.  Bijou is still going through chemotherapy.  Realistically, I know that she doesn’t have very much time left, but she has more good days than bad and, thankfully, seems oblivious to the drama that surrounds her.

I’m also writing to let you know how happy we are that you led us to the Vet Cancer Group in Tustin.  We are seeing Dr. Jarrod Vancil.  He is an incredible vet–knowledgeable, candid, and compassionate with both dogs and their owners.  I feel so fortunate to have him as our oncologist during this difficult time.  At each visit, he provides chemotherapy for the dogs, but he also provides reassuring and much-needed “therapy” for me, the owner.  I just wanted to pass along this information.  The staff at the Vet Cancer Group is also amazing, much like the staff you have at LBAH.  Bijou does not exhibit the fears and anxiety that she did when we were going to the other cancer center.  The staff goes out of their way to make people and animals as comfortable as possible.

Take care, Leslie and Bijou

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