Dogs | Long Beach Animal Hospital - Part 2

Category: Dogs

Symptoms of Diseases

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Here are 5 basic areas you should observe on a daily basis.

Eating

Watch your pets daily eating habits for :

  • difficulty chewing
  • odor
  • swelling
  • pawing at its muzzle

Since dental disease is so prevalent please follow the link to learn how this can affect your pet’s eating.

Breathing

When your pet is at rest count the number of times it breathes per minute (watch it for 15 seconds and multiply that number by 4). A typical dog or cat breathes 30-40 times per minute, although this can be variable based on breed and external temperature. The important thing to watch for is an increase in its respiratory rate over a period of time. Trend this on a piece of paper weekly so you can see this trend as it gets going. This can be a subtle but very important parameter to measure since an increase here can be for many serious reasons.

Urination

Look for any changes in the following:

  • Urinating more often or in greater amounts than normal
  • Urinating small amounts frequently
  • Straining to urinate
  • Inability to urinate
  • Licking at genitals

In female dogs it can be difficult to assess some of these parameters, so try to pay close attention when she squats to urinate.

Defecation

Any significant change here is important:

  • Continual diarrhea of any type
  • Straining to defecate
  • Licking at anus
  • Scooting
  • Any blood on feces

Walking

Obvious lameness is readily noticed. Also look for a pet that is leaning more towards one leg or the other, tires easily after walking or playing, is slow at getting up after resting, or is reluctant to go up or down any type of elevation like stairs or jumping into a vehicle.

Now that you have observed your pets daily habits lets look at how you can look for problems that are not so apparent by going to our In Home Exam page.

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Heart Diseases And Their Treatment

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  1. Chronic Atrioventricular Valve Disease (Myxomatous AV Valvular Degeneration)

    This disease goes by several names. They include endocardiosis, mucoid valvular degeneration, chronic valvular fibrosis and acquired mitral regurgitation/insufficiency. It is the most common cause of heart disease and congestive heart failure (CHF) in the dog. Tricuspid valve regurgitation can also occur with this disease. It is rarely seen in cats.

    Cause

    The exact cause is unknown. It effects the mitral valve more commonly than the tricupid valve, although both can be involved. It probably affects the mitral valve more commonly because of the high pressure in the left ventricle. As dogs age nodules form along the edge of mitral and tricuspid valves. When they get thicker the valves begin to leak (regurgitation), and as the disease progresses, the valves become deformed and shrink. You saw this previously in the necropsy pictures of the dog heart. As the problem progresses the chordinae tendinae might even rupture.

    As the blood regurgitates abnormally backwards into the left atrium it increases the pressure in the atrium, making it harder for blood to flow from the lungs into the heart (from the pulmonary vein to the left artium). As the back pressure increases, the pressure in the veins of the lungs increases to a point (pulmonary hypertension) where the fluid leaks out, leading to pulmonary edema. This regurgitating flow of blood through the left atrium eventually causes it to enlarge (you saw this in the radiograph pictures). The regurgitating blood can go from the left ventricle through this valve and into the left atrium with such force that it causes “jet” lesions in the wall of the left atrium. The left atrium might also develop an arrhythmia as it continues to dilate. The enlarging left atrium can actually tear and cause blood to leak within the pericardial sac.

    Since some of the blood that would normally be ejected by the left ventricle is now regurgitating back into the left atrium there is less flow of blood out of the left ventricle and into the aorta. This can begin the process of poor perfusion, leading to the cascading series of events culminating in congestive heart failure (CHF). Not every case of chronic atrioventricular valve disease will lead to heart failure though. Some dogs can have thickened and deformed valves and never show any symptoms.

    You learned all about this in the anatomy, physiology, and pathophysiology sections previously explained.

    Signalment

    It usually occurs in smaller breed dogs, notably:

    History

    Symptoms might include exercise intolerance, weakness, syncope (passing out), cough, shortness of breath, and lethargy.

    Physical Exam

    A heart murmur along with an arrhythmia is a clue to this disease. As the problem progresses the murmur becomes louder. In the later stages of the disease the fluid that builds up in the lungs (pulmonary edema) can be heard with the stethoscope also. An irregular rhythm and increased heart rate might also be present as the disease progresses. In the early stages of this disease there might not be any abnormalities on the physical exam.

    Diagnostic Tests

    Blood samples are usually normal if only the heart is having a problem. Since these are geriatric patients usually, a blood sample is still indicated to check for other problems in pets this age.

    Radiographs are used commonly to help in the diagnosis. The left atrium is enlarged, and sometimes the left ventricle. We might also find enlargement of the pulmonary veins and even evidence of pulmonary edema.

    An echocardiogram can also give us significant information. The abnormal valves can be seen, along with rupture of the chordae tendinae in some cases. The doppler can actually view the blood regurgitating through the abnormal valve. The left ventricle might also be enlarged.

    This is what mitral regurgitation looks like during a doppler echocardiogram

In the early stages the ECG might be normal. As the problem progresses arrhythmia’s might be present.

Treatment

Surgery and balloon catheter dilation are helpful but may be of limited value. Medical therapy is used to treat this problem if it progresses to CHF.

Medical therapy is utilized to slow the progression of the disease (minimize the compensation mechanism we describe earlier), control the fluid that builds up in the lungs, and decrease the heart rate as the problem worsens. The advent of ACE inhibitors (afterload reducers) has given us the opportunity to help slow the progression of this incurable problem.

Therapy might depend on the stage of the disease. If there is a murmur in one of the affected breeds, but the left atrium is not enlarged, then minimizing sodium (salt) in the diet might be of help. As the murmur intensifies and the left atrium enlarges we will start Enalapril, and continue with the low sodium diet. As the murmur intensifies and the problem progresses we might increase the dose of Enalapril.

When a cough appears lasix will be used, and when the heart starts racing we might add digoxin. If pneumonia occurs or other lung problems become apparent we will also use antibiotics and bronchodilators.

Prognosis

Mildly affected dogs can have a good quality of life for years. It all depends on when the diagnosis is made and when therapy is instituted.

All dogs on therapy for CHF should be monitored every 3-6 months to adjust for changes. This includes a blood panel with thyroid, a chemistry panel, ECG, and chest radiographs.

Chronic atrioventricular Valve Disease can mimic infectious endocarditis, which is an actual infection of these valves caused by a bacteria. This is a serious disease that can cause significant illness.

Some of the more common bacteria are:

Strep. spp.

Staph. spp.

E. coli

Pasteurella spp.

Klebsiella

These bacteria arise from infections of the gums, skin, urinary tract, prostate, lungs, and internal organs. The infection can spread to the spinal cord, causing a disease we call diskospondylitis. It is treated the same way, since CHF is present. In addition we will use antibiotics for up to several months to control the infection.

  1. Cardiomyopathy

    Cardiomyopathy is a disease where the actual heart muscle (myocardium) becomes weak and unable to contract with sufficient force (decreased contractility leading to a decreased stroke volume) to provide adequate perfusion (reduced cardiac output) for the cells of the body. Pets that get cardiomyopathy have a poor prognosis in general.

    There are three types of cardiomyopathy:

    1. Dilated

      The heart muscle is weak and flabby, and does not have the strength to contract with enough force to provide adequate perfusion of the cells. This form is rare in cats now because of supplementation with Taurine.

      This is the heart of a cat with this disease. The forceps are pushing on the ventricles and showing how flabby they are.

      Feline-DilatedCardiomyopathyHeart

    2. Hypertrophic

      The heart muscle has become so thickened that the left ventricle chamber is too small to allow an adequate amount of blood to flow into it (diastole) before it contracts (systole) and perfuses the cells of the body. It is like a bodybuilder who is too buff to move efficiently.

      This is the form of the disease that is prevalent in cats. The heart muscle might hypertrophy due to hypertension or problems with the outflow tract of the aorta.

       The bottom tiny opening (arrow) is the left ventricle surrounded by excessive thickened heart muscle.  The opening should be 4x this size. You can see it is just too small to hold enough blood to be pumped out of the aorta to the cells of the body.

      Feline-HypertrophicCardiomyopathyArrow

      This increase muscularity of the left ventricle increases pressure in the left atrium, causing it to dilate. This increases the pressure in the pulmonary veins leading to pulmonary edema. Pulmonary edema (congestive heart failure) is fluid in the lungs, and is a serious end consequence of cardiomyopathy.

      This arrow points to the dilated left atrium, which is 2x larger than it should be

      Feline-HypertrophicCardiomyopathyArrowLA

    3. Restrictive (Intermediate)

      This form has characteristics similar to dilated and hypertrophic. Cats with this problem have scar tissue instead of normal heart muscle. The scar tissue decreased the strength of the heart, so it pumps out less blood at each beat (decreased stroke volume).

      The diseased heart muscle beats irregularly (arrhythmia) and does not have the contractility to pump blood to the rest of the body (decreased cardiac output). This leads to the congestive heart failure we described in the pathophysiology section. In some cases there is sudden death from the arrhythmia that occurs.

    Cause

    Viruses, toxins, drugs, and taurine deficiency are suspected as causes. In most cases, especially in the breeds that are prone to this problem, the cause is unknown.

    Signalment

    This disease occurs in large breed dogs like the Great Dane, Labrador, German Shepherd, St. Bernard, Irish wolfhound, English cocker spaniel, Scottish deerhound and Boxer. It is especially prevalent in Doberman pinschers. Most of these dogs are males and get the dilated version of cardiomyopathy.

    Even though dogs of any age can get this problem, the tend to me middle aged. Dilated cardiomyopathy also occurs in Burmese, Siamese, and abyssinians.

    History

    The symptoms noted are those of congestive heart failure (CHF). Typical symptoms include weakness, poor appetite (anorexia), cough, breathing difficulty (dyspnea), weight loss collapse (syncope) and distended abdomen (ascites). In some cases sudden death occurs before any symptoms.

    Some Doberman pinschers can have this disease and not show symptoms for several years. By then the prognosis is poor.

    In cats the symptoms are similar. Unfortunately, a significant number of cats do not show any symptoms, they just have a sudden death. Cats also get paralyzed in their back legs because of a blood clot (thrombus) that enters the blood vessels to the back legs. This is called a “saddle thrombus” because it occurs at the point where the abdominal aorta branches into each of the arteries that supplies the rear legs with blood. The blood clot arises from the pooling of blood that occurs in the left atrium secondary to the hypertrophy of the left ventricle (described above in the hypertrophic section). These cats are in significant pain, and palpation of the rear legs might reveal a cooler temperature than the rest of the extremities. The prognosis is poor for this form of feline cardiomyopathy.

    To get you oriented, this cat’s head is towards the left and the back legs are towards the right. Blood coming from the heart flows down the abdominal aorta (labeled as artery in this picture) and towards the rear legs. at the vertical arrow the abdominal aorta branches into the internal and external iliac arteries. From there it goes into the femoral arteries to supply the rear legs with freshly oxygenated blood. The poorly oxygenated blood returns to the heart through the femoral vein, then the iliac veins, and eventually the caudal vena cava (labeled as Vein in this picture). At the vertical arrow is where the saddle thrombus forms.


    The thrombus (vertical arrow) is now apparent when we open up the arteries

    This is the way the artery is supposed to look when there is no thrombus

    You can see why it is called a “Saddle Thrombus”

    Here is a different cat with the same problem. In this picture the head is to the right, the snake-like clot is getting started at the right side. The large clot blocking the entrance to the blood vessels that supply the rear legs is apparent in the middle of the picture. The blue color to the rear leg vessels on the left is due to a clot that extends into them from the main clot in the center.

    Removing the large clot

    You can see the very smooth wall of the aorta with the clot removed

    The heart with a large clot in one of the chambers is the source of the clot in the aorta and legs. The clot is the dark structure in the middle of the heart towards the top.

    Physical Exam

    Abnormalities found during an exam are similar to other heart diseases and even other diseases in general. Auscultation of the thorax might reveal an arrhythmia and high heart rate. There might even be a pulse deficit if atrial arrhythmia is present. a murmur might be found in some pets with cardiomyopathy, although not every pet with a murmur has this disease.

    Cats with a saddle thrombus might have weak or non existent femoral pulses. They will be painful and might not be able to use the rear legs.

    Diagnostic Tests

    The ECG can pick up arrhythmia’s caused by cardiomyopathy, in some cases prior to the onset of congestive heart failure. In breeds that are highly prone to this problem like the Doberman pinscher, it is advised to perform an ECG yearly to monitor for these changes.

    On a radiograph the heart will appear enlarged because of the dilatation of all the chambers. Pulmonary edema and congested veins are indications of congestive heart failure secondary to cardiomyopathy.

    The radiograph of this cat with cardiomyopathy and saddle thrombus shows the classic signs of an enlarged heart

    Feline-HypertrophicCardiomyopathyLateral

    Feline-HypertrophicCardiomyopathyDV

    Some Boxers with cardiomyopathy will have normal appearing hearts on a radiograph.

    In many pets an echocardiogram is the most conclusive means of diagnosing HCM.

    This is an echocardiogram of the cat with the enlarged heart above. The echocardiogram showed an enlarged papillary muscle in the ventricles. We could even visualize the blood swirling around as it formed a pre-clot that would eventually become a thrombus and expelled from the ventricle to large in some artery in the body.

    We could even visualize the thrombus at the end of the aorta just before it branches into the iliac arteries

    Treatment

    Routine treatment for congestive heart failure and arrhythmias is used. The effectiveness of therapy depends on the severity of the disease and how long the problem has been present. Some dogs and cats can do well for several months and even years if treated early enough.

    Since the arrhythmia that occurs with cardiomyopathy can be detected before the onset of congestive heart failure, it is obvious that checking for this problem is important, particularly in Doberman pinschers and Boxers. Doberman pinschers with atrial fibrillation and dilated cardiomyopathy have a poor prognosis.

    Cats might also be treated with aspirin to prevent a saddle thrombus. It is imperative that cats are kept in a relatively stress free environment.

    The best long term approach for dogs and cats is not to breed lines that are prone to this problem.

  2. Heartworm

    Cause

    Heartworm is caused by a parasite called dirofiliaria immitis. It is spread to dogs, and recently cats, by a mosquito. The mosquito is a necessary part of the life cycle.

    In an affected dog or cat, female heartworms that reside in the pulmonary artery release small larval forms called microfilaria. Microfilaria circulate in the bloodstream for many months, and even sometimes years. If a mosquito bites a dog or cat that has circulating microfilaria it ingests them. These larva go through changes in the mosquito over the next 2 weeks. When this mosquito bites a dog it injects this larvae into a new dog. The larvae continue to develop in this dogs tissue and eventually become adult heartworms in the heart or pulmonary arteries 6-7 months later.

    Traditionally this disease only occurred in hot and humid states that were essential to mosquito breeding. The disease occurs throughout our country now, although heatworm preventive medications have had a significant effect in lowering the incidence of heartworms.

    Pathophysiology

    The degree of heart disease that occurs depends on the number of heartworms, how long they have been present, and how the immune system reacts to them.

    The actual presence of the worms in the arteries induces an inflammatory reaction causing blood clots (thrombi) to form. It also causes fluid to leak out of the artery into the surrounding tissue. Eventually pulmonary hypertension develops leading to an enlarged right ventricle as it works harder to pump the blood against all this pressure (afterload).

    If a large number of worms are present they can literally fill up the right atrium and caudal vena cava. Not only does this interfere with the proper flow of blood through the heart, it also causes changes in the red blood cells and clotting system. In serious cases this can cause a bleeding disorder called disseminated intravascular coagulation (DIC).

    The immune system can destroy the microfilaria released by adult heartworms in the pulmonary capillaries, resulting in a negative heartworm test. This is called occult heartworm disease.

    Signalment

    Dogs and cats of any breed can be infected, although we tend to see it more in large male dogs. Since it takes at least 6 months from the time a mosquito injects microfilaria into a dog until these microfilaria become adult heartworms, puppies must be at least 6 months of age before adult heartworms are present. Most dogs are diagnosed at middle age.

    History

    Many dogs do not have any symptoms until heart failure progresses. This emphasizes the need for yearly testing. When symptoms occur they can include:

    Poor appetite

    Weight loss

    Coughing

    Lethargy

    Difficult breathing

    Exercise intolerance

    Distended abdomen

    These are the symptoms of general heart failure, yet they can also occur in other diseases besides heartworm.

    Physical Exam

    In many cases the physical exam is normal. As the disease progresses the following exam findings might occur:

    Cough when the windpipe (trachea) is palpated

    Increased respiratory rate (tachypnea)

    Increased lung sounds (crackles) when ausculting the chest with a stethoscope

    Diagnosis

    Radiographic changes that might occur include an enlarged right heart along with an enlargement of the pulmonary artery. Several smaller arteries might be dilated, tortuous, or pruned. Other changes are similar to those that occur with right heart failure.

    An EKG might show changes indicative of right heart enlargement.

    A routine blood panel might reveal an elevation of certain types of white blood cells called eosinophils and basophils. There might even be an elevated protein level and evidence of kidney problems.

    Microfilaria detection is the best and most accurate way to diagnose adult heartworms. We can see them microscopically when we look at a blood smear from an infected dog. Unfortunately, this diagnostic method is unreliable due to the small size of the microfilaria in relation to the large amount of blood in the bloodstream. Several tests were developed to increase our ability to see these microfilaria on the blood smear. They made a major improvement in diagnostic ability, but are still not as good as immunodiagnosis.

    Immunodiagnosis involves looking for antigens of microfilaria or antibodies against the microfilaria using monoclonal antibody techniques. Several of these tests can be used in our office, therefore you get the report within 30 minutes. If the test is negative, then your dog or cat probably does not have heartworm. Unfortunately, reproductively inactive female adult heartworms, along with male heartworms, will also show up negative on these tests. This is called occult heartworm disease. On occasion, false positives can occur, particularly if other parasites (roundworms, etc.) are present or there is another nonpathogenic heartworm present called dipetalonema reconditum.

    Approximately 15% of the heartworm infected dog have occult heartworm disease. In occult heartworm disease there are adult heartworm parasites in the pulmonary arteries yet there are no microfilaria circulating in the bloodstream. Since the primary method of diagnosis is detection of these microfilaria, either visually, or with monoclonal antibody tests, it is possible to miss a diagnosis.

    There are several reasons why occult heartworm disease might occur. It happens early in the course of infection when adult female heartworms have not had enough chance to release microfilaria to any significant extent. At the other end of the spectrum, old adult heartworms might not release microfilaria. It can occur if mostly male heartworms are causing an infection, since they do not release microfilaria. It can also occur if adult heartworms are present and your dog is on heartworm preventive medication. Finally, it can occur if the immune system produces antibodies to microfilaria, suppressing their numbers so low that they are not detected with current monoclonal antibody techniques. Unfortunately, in this scenario there is significant pathology to the lung tissue because of this immune system reaction. These dogs usually present with severe breathing problems.

    In general, we are starting to encounter dogs with adult heartworms that have minimal circulating larvae. This is making diagnosis more difficult.

    Treatment

    This is a disease where the treatment is almost as bad as the disease. No treatment is completely effective although the dog or cat feels substantially better. The worms that are killed can block small blood vessels and cause thrombosis. If large numbers of heartworms are present there can be a massive amount of thrombosis. This can increase pulmonary hypertension and lead to additional fluid buildup in the lungs, even leading to disseminated intravascular coagulation. The inflammatory reaction that occurs can also affect the glomeruli of the kidneys. All treated dogs need to rest to minimize a reaction from the dead heartworms.

    If a dog is already in heart failure it needs to be stabilized prior to treating the adult heartworms. This includes the routine treatment for CHF, particularly diuretics, digoxin, Enalapril, exercise restriction, and aspirin.

    The primary drug used to treat adult heartworms is melarsomine. It has arsenic as its active ingredient, although side effects are less than previous arsenic treatment for heartworms. It still has the potential to cause problems with the kidneys (nephrotoxicity) and liver (hepatotoxicity), so close monitoring is vital. Dead heartworms can still cause a pulmonary allergic reaction with its associated problems. This problem is partially mitigated by giving melarsomine over a 2 day period of time instead of all at once. If your dog has severe heartworm disease it might be given one treatement, then sent home to rest for one month. At that time, it is given a full dose over 2 days.


    Another treatment modality used by some veterinarians is to use heartworm preventive medications at a modified dose to slowly kill adult heartworms over 16 months. The theory is that the slow killing of the worms will minimize reaction from the death of adult worms. The disadvantage to this slow killing involves the damage the adult heartworms can cause during that time.

    In some cases we use aspirin or cortisone as an adjunct to our routine therapy. These drugs minimize blood clots, platelet problems, and inflammation.

    Once the adult heartworms are killed the microfilaria that are circulating in the bloodstream are our next target. The drug of choice, except in Collie breeds who can have a serious reaction, is Ivermectin. In Collie breeds we use a drug called Levamisole.

    Since heartworm is such a serious disease, and treatment has potential toxicity, it is obvious that prevention is the best way to go. There are many products that are highly effective at preventing heartworms. They all should be started within one month of the mosquito season, and continued to the end of the mosquito season. Since many of these preventatives also control fleas and internal parasites, we recommend their use year round. Except for Revolution, your dog must be tested negative for heartworms prior to instituting these preventive medications.

    These preventive medications need to be given monthly. If your dog does get adult heartworms because you did not follow the montly schedule you set up a diagnostic problem. These dogs will have so few circulating microfilaria that we might not be able to make an accurate diagnosis.

    Some of the more popular ones are:

    Trifexis- It prevents heart worm, kills fleas, and treats for roundworms, hookworms, and whipworms. Its one of most recommend and used products.

    Heartgard and Heartgard Plus- They contain Ivermectin, and can be safely used in Collies over 10#. In addition, Heartgard Plus kills internal parasites. It is given on a monthly basis.

    Interceptor- It contains milbemycin, which in addition to preventing heartworms also kills circulating microfilaria and sterilizes adult heartworms. It is also given on a monthly basis.

    Sentinel- It contains milbemycin and lufeneron, so in addition to its ability to prevent heartworms, it controls roundworms, hookworms, whipworms and flea eggs.

    Revolution- It contains the drug Selamectin, which is similar to Ivermectin, but much more broad spectrum in action. An advantage of Revolution is no adverse reaction if the dog already has microfilaria circulating from a current adult heartworm infection. In can be used safely in Collies, and treats and controls fleas in dogs and cats, ear mites in dogs and cats, sarcoptic mange and ticks in dogs. It even treats hookworms and roundworms in cats.

    In general, the prognosis for dogs with heartworm disease is good. As is usually the case, it depends on the number of worms present, how long the disease has been occurring, and how the immune system is reacting. Although all of the worms are not usually killed, their decrease results in significant breathing improvement in almost all dogs.

    Feline Heartworm Disease

    Heartworm disease in cats is similar to dogs, yet there are some significant differences. Symptoms can range from none to sudden death or chronic illness. Most do not have any symptoms. If they are present, they usually include breathing problems (similar to asthma) and vomiting. They usually have less worms and more occult heartworm disease. Circulating microfilaria are not detectable with the microscope, and diagnosis using other means is difficult. Melarsomine is not used to kill adult heartworms, Thiacetarsamide, the original drug used to treat dog heartworms, is used in place of melarsomine. Preventive medication should be used for cats in addition to dogs. These include Revolution and HeartGard for Cats.

  3. Aortic Stenosis

    Cause

    This disease of dogs arises when abnormal tissue near the aortic valve obstructs the flow of blood out of the left ventricle. If severe enough it can eventually lead to CHF and ventricular arrhythmias.

    Signalment

    It usually occurs in large breed dogs, notably:

    Newfoundland’s

    Golden Retrievers

    Rottweiler’s

    Boxers

    German Shepherds

    History

    Symptoms include exercise intolerance, rear limb weakness, syncope (passing out), cough, shortness of breath, and even death.

    Physical Exam

    A heart murmur along with an arrhythmia is a clue to this disease.

    Diagnostic Tests

    Radiographs and electrocardiograms are of help in the more advanced cases. Echocardiograms are helpful in the moderate to severe cases.

    Treatment

    Surgery and balloon catheter dilation are helpful but may be of limited value. Medical therapy is used to treat CHF.

    Prognosis

    Mildly affected dogs can have a good quality of life. If the problem is more severe the prognosis is not as good.

  4. Pulmonic Stenosis

    Cause

    This disease of dogs arises when abnormal tissue near the pulmonic valve obstructs the flow of blood out of the right ventricle. If severe enough it can eventually lead to an enlarged right heart and regurgitation of blood through the tricupid valve and into the right atrium. If severe enough right sided CHF might occur.

    Signalment

    The following breeds are know to be prone to pulmonic stenosis:

    Beagle

    Chihuahua

    English bulldog

    Keeshond

    Samoyed

    Mastiff

    Newfoundland

    Boxer

    Terrier breeds

    Spaniel breeds

    History

    Many dogs have no initial symptoms. If symptoms are present, they might include exercise intolerance, ascites, syncope (passing out), shortness of breath, and even death.

    Physical Exam

    A heart murmur along with distended jugular vein might be present.

    Diagnostic Tests

    Radiographs and electrocardiograms might show right ventricular enlargement. Echocardiograms are helpful in many cases.

    Treatment

    If the problem is severe enough surgery is used to correct the problem. This depends on exactly where the problem is in this valve along with other blood vessels to the heart. Balloon catheter dilation can also be used.

    Medical therapy is used if CHF is present. When the CHF is stabilized surgery might be utilized.

    Prognosis

    Mildly affected dogs can have a good quality of life. If the problem is more severe the prognosis is not as good. These dogs should be monitored yearly for changes in their condition.

  5. Pulmonic Stenosis

    Cause

    In this disease an abnormal opening occurs between the ventricles, which allows blood to flow directly from the left ventricle (higher pressure) to the right ventricle (lower pressure). This disease occurs in dogs and cats. The severity of this disease depends on exactly where the opening is located and how big it is. Eventually left sided CHF can occur because of an overload of blood to the left ventricle as more blood is shunted through the right ventricle, leading to more blood flowing through the lungs, leading to more blood flowing back into the left atrium and left ventricle.

    Signalment

    The following breeds are know to be prone to PDa:

    English bulldog

    English springer spaniel

    History

    Many pets have no initial symptoms. If symptoms are present, they might include coughing and shortness of breath as CHF develops

    Physical Exam

    A heart murmur is commonly present.

    Diagnostic Tests

    Radiographs and electrocardiograms might show left ventricular enlargement and distention of the pulmonary vessels. Echocardiograms are used to confirm the diagnosis.

    Treatment

    Many pets need no treatment at all. Surgery is difficult to perform. Medical Therapy is used to treat CHF if it occurs.

    Prognosis

    Prognosis is good if the opening is small. Larger defects need to be monitored yearly.

  6. Patent Ductus Arteriosis (PDA)

    Cause

    In the uterus the mother of the dog supplies the dog with its oxygen since obviously a puppy in the uterus is not breathing. One of the mechanisms of the body to bypass the lungs of the pup is to flow the blood directly from the pulmonary artery to the aorta. When the pup is born, this direct communication between these vessels closes, the blood now flows from the pulmonary artery to the lungs to get its oxygen. This disease of dogs occurs when the communication between the descending aorta and the pulmonary artery fails to close after birth. This abnormal flow of blood overloads the left side of the heart, leading eventually to CHF.

    Signalment

    The following breeds are know to be prone to PDA:

    Collie

    Maltese

    Poodle

    Pomeranian

    English springer spaniel

    Keeshond

    Bichon frise

    Yorkshire terriers

    Shetland sheepdogs

    German shepherds

    History

    Many dogs have no initial symptoms. If symptoms are present, they might include coughing and shortness of breath.

    Physical Exam

    A heart murmur called a continuous (occurs during systole and diastole) murmur, is a clue to this disease.

    Diagnostic Tests

    Radiographs and electrocardiograms might show left ventricular enlargement and distention of the pulmonary vessels. Echocardiograms are helpful but not needed in many cases.

    Treatment

    A surgical procedure that closes this abnormal connection is used to treat PDA.

    Prognosis

    Prognosis is good if surgery is performed before the symptoms of CHF start appearing.

Medical Treatment of Heart Disease

The medical management of animals with CHF (congestive heart failure) is aimed at controlling the deleterious effects of the underlying pathology. These effects typically include pulmonary congestion and edema, cardiac arrhythmias, reduced cardiac output, and excessive vasoconstriction. Many medications are used to treat heart disease. In almost every case they can only control the symptoms, and hopefully, slow down the progression of the disease. In general, medications used to treat cardiac disease, especially CHF, are highly beneficial. The goal of therapy is to improved the quality of life of these pets while simultaneously minimizing the side effects of the drugs used. Most pets will not go back to being able to exercising vigorously, as a matter of fact, too much exercise can destabilize compensated dogs and cats.

Therapy needs to be tailored made to each pet, and again, constant monitoring is needed to adjust for any changes that are occurring. This means that blood panels, radiographs, ECGs, and blood pressure need to be checked weekly initially, then every 3-6 months, assuming the heart failure is under control.

Cardiac disease is commonly diagnosed in geriatric patients that have other problems simultaneously. Some of the medications used to treat heart disease can exacerbate other medical problems common in geriatric patients. Using these medications properly tends to be a balancing act, minimizing their deleterious affects while maximizing their advantageous properties. This is particularly true if a pet has kidney disease along with heart disease. This balancing act requires constant monitoring.

Many drugs are used in cardiovascular disease. We will go over the more common treatments, especially in regards to congestive heart failure.

ACE (Angiotensin Converting Enzyme) Inhibitors

These drugs are a part of the treatment plan of almost every dog with CHF. The addition of Enalapril or Benazapril to conventional therapy in dogs with chronic congestive heart failure resulted in a significant decrease in clinical signs and a 92% increase in survival time. The use of vasodilators, such as Enalapril, increase the survival time of dogs with CHF. This is especially true in CHF from cardiomyopathy, but does not necessarily apply to dogs with CHF from mitral insufficiency.

They add to the quality of your dogs life by minimizing the fluid buildup in the lungs (pulmonary edema) and abdomen (ascites).

In general, ACE inhibitors lower the blood pressure (decrease afterload) and decrease salt and water retention. They work by inhibiting the conversion of angiotensin I to angiotensin II in the lungs. We discussed this in the Cardiac Anatomy and Physiology section of our heart disease page. This decreases fluid buildup in the lungs, thorax, and abdomen, and it also makes it easier for a weakened or enlarged heart to pump the blood out into the bloodstream. Kidney values and electrolytes should be monitored while on ACE Inhibitors.

The more common ACE inhibitors we use are Enalapril, benazepril, and captopril. Enalapril is approved for use in the dog by the FDA, and is the most common ACE inhibitor we use. ACE inhibitors can take up to 7 days to produce beneficial effects, and need to be constantly adjusted to maximize their benefits.

ACE inhibitors are commonly used in people that have high blood pressure (hypertension), even if they do not have heart failure.

Diuretics

Diuretics (usually lasix) are the mainstay of treatment for CHF, and should be used in conjunction with ACE inhibitors. Lasix is a loop diuretic. That means it has its effects on a section of the kidney called the loop of Henle. It is here that lasix causes more sodium (salt) to be excreted from the body. Sodium pulls water with it when it is excreted, so urination increases and fluid level of water in the bloodstream decreases. This decreases the blood pressure in the capillaries, so less fluid leaks out into the lungs (pulmonary edema) and abdomen (ascites). Another medication, called spironolactone, is also used with lasix, or in place of it.

Overuse of diuretics can cause dehydration and can interfere with normal kidney function. As was already mentioned, lasix use should be monitored with a blood panel every 3-6 months to assess kidney function. As a geriatric pet ages, the kidneys and heart can both have disease, so the use of lasix is a balancing act between these two diseases. It is rare for a dog to need potassium supplementation (K+) while on a diuretic, unlike people. Your pet will drink more than usual, so make sure fresh water is available at all times.

As a rule of thumb, if a dog or cat in congestive heart failure increases its respiratory rate routinely beyond 30 breaths per minute, we give additional lasix. It is better off to remove the fluid from the lungs and let the red blood cells get oxygen to deliver to the cells, at the expense of the kidneys, than to treat the kidneys with extra fluids to flush waste products out, and have the lungs fill up with more fluid. The more we are able to run diagnostic tests to monitor this, the better we can titrate the diuretics and fluids.

Pimobendan (Vetmedin)

This FDA approved drug is in a class of drugs called indodilators. This means it increases the strength of the contraction of the heart muscles (ventricles).  This is called a positive inotropic effect.

It also helps dilate the peripheral blood vessels, decreasing afterload, and making it easier on the heart to push the blood into the arteries. If you review our heart anatomy and physiology page you will learn much more about all of this.

This drugs has been a major help in the treatment of congestive heart failure due to dilated cardiomyopathy or endocardiosis. It increases survival time and quality of life in these patients.

Diet

Minimizing salt in the diet is beneficial in preventing fluid buildup (ascites of pulmonary edema) only when the fluid is present. If you start a restricted sodium diet too soon you can actually cause the opposite effect.

Typical food include Hills K/D and H/D. Many pets eat these foods well, but if they have diminished appetite on these foods then they are of no benefit, since they will continue to lose weight and be lethargic.

Supplements

Supplementation with Omega 3 fatty acids might be of help, along with carnitine and taurine in specific cases of dilated cardiomyopathy. Carnitine will only be effective in a small number of dogs. To know for sure if a dog is carnitine deficient, a biopsy of the heart muscle is needed.

Coenzyme Q10 is also used, although this has not been proven to be effective either.

Exercise Restriction

If your dog or cat has heart failure it needs to stay relatively inactive. The heart is already compromised and working at maximum capacity, and does not have the capacity to increase cardiac output.

Cardiac Emergency

Some pets are presented to us having severe difficulty breathing from pulmonary edema. They need to be handled very carefully since they are literally drowning in the own fluids and unable to get air. It would be like a person firmly holding a pillow over your face.

These pets might need:

100% Oxygen

Nitroglycerin to dilate the blood vessels and decrease the after load.

We use gloves to put the nitrogylcerine on the ears since it is absorbed through the skin


Intravenous lasix to reduce pulmonary edema

Intravenous morphine to dilate the blood vessels and decrease the afterload

Intravenous sodium nitroprusside- potent arterial and venous vasodilator, needs constant blood pressure monitoring. Reduces afterload

We might use low levels of low sodium intravenous fluids to help the kidneys if they are failing also. We cannot thoroughly flush out kidney waste products because this much fluid given intravenously will exacerbate the pulmonary edema that is already present. Once the emergency is under control we might be able to slowly increase these fluids.

Oral medications have no place in these dogs since they are usually anorectic and likely to have minimal GI motility. In addition, they are unable to absorb the medication through their intestines and into the bloodstream because blood is being shunted away from the intestines and to the vital organs.

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Asthma

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Asthma is a problem we tend to see much more often in cats than dogs, with the Siamese cat being the most prevalent breed. Anyone who has ever had an asthmatic attack has an idea of what these cats go through when they can’t get their breath. Its like trying to breathe with a pillow pressed against your nose and mouth.

This disease goes by several names- feline bronchial disease, allergic bronchitis, and allergic airway disease.

Graphic photos on this page.

A glossary of medical terms will be used in this page:

dyspnea- difficult breathing tachypnea- fast respiratory rate
pneumothorax- excess air in the thorax bronchi- large breathing tubes in the thorax
alveoli- where oxygen goes from lungs to the blood thorax- chest
pneumonia- infection in the lungs hypertrophy– excessive growth of a cell or organ
necropsy- animal autopsy bronchiole- small breathing tubes in thorax
bradycardia- low heart rate

Normal Physiology

In the normal thorax inhaled air is brought to the lungs through progressively smaller breathing passages. It starts with the trachea (windpipe) and progresses to bronchi and bronchioles, eventually ending at the actual lung tissue called alveoli. It is at the alveoli that oxygen is absorbed by red blood cells on inhalation and carbon dixode is excreted on exhalation.

These breathing passages contain smooth muscle that controls their size. This is the type of muscle that works automatically without you consciously telling it what to do as part of the autonomic nervous system. Our VNA page has spinal anatomy to show the nerve pathways that accomplish this. When these muscles are relaxed the air passages and lung tissue are fully open and breathing is effortless. When they contract (called constriction) the airways narrow dramatically and it is difficult for air to make it all the way to the lung tissue where it exchanges oxygen for carbon dioxide. The size of these breathing passages, especially the bronchioles since they are small in diameter, can have a substantial influence on how much air makes it all the way to the alveoli.

These are the lungs taken during a necropsy. The lungs are sponge-like and have an extensive blood suppy. You can see just a small portion of the blood supply- it is the three vertical and bluish vessels going from the heart to the lungs at the bottom of the picture. Within the actual spongey lungs there is an extensive network of small blood vessels.

The lungs have an extensive network of passages and blood vessels. This barium radiograph illustrates just some of those breathing passages. The barium outlines the major bronchi, the 4 large white breathing passages below. All the fainter  diffuse whitish area in the lungs below are barium in the small bronchi and alveoli. You can see how extensive this network is.

Since we are an exotics practice, we thought it might be fun to show you the air filled lungs of a bearded dragon. The heart is the purplish and round structure to the upper left of the picture. The lung is the air filled and mesh appearing structure in the middle of the picture.

The lungs are very sensitive and easily damaged. The dark areas on this lung were caused by trauma- this pet was hit by a car. This is called a pulmonary contusion.

Pathophysiology

Something (smoke, pollen, perfume, pollution) stimulates the bronchi and bronchioles, causing them to become inflamed and swell (edema). This sets up a hypersensitivy reaction causing the smooth muscle in them to constrict.   Sometimes the smooth muscle hypertrophies (gets larger) and causes long term problems.

When the smooth muscle in the bronchi and bronchioles constrict  breathing becomes harder. In addition, cells that normally produce mucous in small quantities might increase their production and literally clog up the air passages. If enough mucous production and constriction occurs the alveoli are unable to exchange oxygen and carbon dioxide to the red blood cells. Obviously, this is a serious problem because your pet can no longer exchange oxygen and carbon dioxide at the alveoli. This is crucial to say the least.

A type of white blood cell called eosinophils starts releasing chemicals known as mediators. These chemicals cause scarring of the breathing passage adding to the problem.

Unfortunately, chronic asthma can increase the blood pressure (hypertension) in the lungs leading to potential failure of the right side of the heart. It can also progress and cause emphysema.

Cause

In most cases we do not know the cause, which of course is frustrating. Risk factors include cigarette smoke, marijuana smoke, dusty cat litter, air or scented fresheners, and any aerosol-like deodorant or hair spray.

Litter that is scented, is dusty or finely ground and has clay in it, can be a problem. Some cats get the problem when exposed to litter made from pine or cedar, especially if they have been treated.  Sometimes litter that is made from newspaper, corn, wheat, or wood pellets can be helpful.  Clean the litter pan more often to prevent noxious odors.

Tobacco and marijuana smoke are very toxic to animals. In additon to predisposing dogs and cats to respiratory disease in general, this smoke is a potent stimulator of asthma in cats. Even the smoke that lingers on your clothes and breath can cause a problem, so smoking elsewhere does not prevent this problem. Scented candles and the burned wood in your fireplace are also implicated.

Our households are drowning in a world of chemicals. These chemicals can trigger and allergic reaction. This includes cleaning products, fabric softeners, carpet cleaners and air fresheners, shampoo and soap, hair dye, baby powder, furniture polish, paint, perfume and cologne- you get the picture.

A type of allergy, called allergic inhalant dermatitis, is caused by grasses, trees, shrubs, pollen particles, house dust molds, bed bugs and mites. These allergens usually cause a skin condition, manifested by excess itching and licking. These same allergens can set off an asthmatic attack.

Food allergies can also be a significant factor with asthma and skin conditions in cats. The allergy can be due to the beef, fish, corn, milk, wheat, or gluten that is in many foods. Even foods that have not caused a problem in the past can trigger an allergic reaction some time in the future. One of the foods we have found most beneficial when we suspect a food allergy is Hills Z/D or Ultra. It must be fed for up to two months to see if it is working. To confirm the food allergy you need to feed the original food and see if the asthmatic or skin problem recurs.

Stress can add to the problem. Cats do not like abrupt change in their daily routine, so take it slow whenever you make a change. Children, travel, fireworks, guests, repairmen, gardeners, maids, etc can all be a source of stress that adds to the problem. Diseases like diabetes mellitus and kidney disease can add chronic stress, especially when giving insulin injections or SQ fluids.

Symptoms

Symptoms of asthma can be chronic, acute, or intermittent. The classic signs of a cat with asthma are wheezing or coughing. If you are observant you might have noticed an slight increase in your cats respiratory rate or effort prior to the wheezing or coughing. Other symptoms are sneezing and labored breathing. As time progresses you might even observe a poor appetite (anorexia), weight loss, or lethargy, although these are not common symptoms.

The wheezing or coughing can vary in severity. Your cat might extend its neck or even breathe with an open mouth when severe. If mild all you might notice is an increased respiratory rate when your cat is at rest.

This cat has severe dyspnea due to asthma. It is in a special cage that supplies 100% oxygen. We will not touch this cat for treatment or diagnostic tests until the 100% oxygen has had a chance to help.

We will constantly monitor this cat using a Pulse Ox (Pulse Oximeter).  It measures the percentage of oxygen in the hemoglobin of the red blood cells (rbc’s). It should be in the mid to high 90’s.We usually take a quick baseline pulse ox on a cat presented during an emergency, then compare it later after it has been on 100% oxygen to determine when it is OK to remove the cat from the 100% oxygen.

Our human volunteer is showing you how it works, and her readout. She is normal, although she was nervous when we filmed her, which is why her heart rate is 83 beats per minute.  Her oxygen saturation (SpO2) is 98% percent, so we don’t have to put her in the oxygen cage!

As a comparison, birds can get many breathing conditions. When presented in this advanced state the problem has been present for a long period of time usually, and the prognosis is poor.

Diagnosis

Cats are masters at hiding problems, so by the time a diagnosis of asthma is made the disease process has usually been present for a significant period of time. This emphasizes the importance of close observation of your cat and a physical exam if you suspect a problem. Our In Home Exam section can show you what to monitor at home before you pet is ill.

Numerous other diseases cause similar symptoms, so the diagnostic process should help differentiate them. Some of these diseases that have similar symptoms include:

  • Heartworm
  • Pulmonary contusion (you saw a picture of this above)
  • Diaphragmatic hernia – a tear in the diaphragm, the muscle of respiration
  • Pleural effusion- fluid build up in the thorax and around the lungs
  • Chylothorax- lymphatic fluid build up in the thorax and around the lungs
  • Lung worms
  • Heart disease
  • Cancer
  • Heart failure (cardiomyopathy)
  • Pneumonia

Signalment

Mostly cats, with Siamese cats being the most prevalent breed. Most of these cats are young to middle aged.

History

The classic signs of wheezing and coughing, for a variable period of time prior to exam. Sometimes these cats cough in a crouched position while extending their necks. Other diseases like lungworms, heartworms, heart failure, foreign bodies, tumors in the lungs and fluid in the thorax can all cause coughing in cats. Asthma is the most common cause of coughing though in the cat.

Physical Examination

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

The trachea (windpipe) might be sensitive and elicit a cough upon palpation. An increased respiratory rate might be noted, along with increased lung sounds on auscultation with the stethoscope. The lungs sounds might be crackles or wheezes. There might even be normal lungs sounds in the presence of asthma.

More expiratory effort vs inspiratory effort might be noted. This could even include an abdominal push. Heart rate can be low (bradycardia), normal, or high (tachycardia).

In severe cases there might be open mouth breathing and blue discoloration of the mucous membranes (cyanosis). Cyanosis is a serious sign and needs immediate attention.

Diagnostic Tests

Blood Panel

A blood panel might show an increase in a white blood cell called eosinophil. This is not a consistent finding though.

This is what a typical CBC (complete blood count) reports. This cat has elevated eosinophils as can be seen in the underlined areas. The top underlined area shows 22% eosinophils when up to 12% is normal. The bottom underlined area shows 4906 eosinophils per cc when the maximum should be 1500.  Sometimes this is a sign of parasites or asthma, sometimes there is no significance to it. If it goes higher it even could be a sign of hypereosinophilia syndrome.

Radiography

Radiographs are an important tool in diagnosis, although a normal radiograph is not uncommon even if your cat has asthma.

This is a normal chest radiograph in a cat. All the dark areas are lung or windpipe. They are dark because they are filled with air. This is what we want to see. The picture below labels the organs.

The anatomy is labeled for better understanding
T- trachea (windpipe)
L- lung
A- aorta
H- heart
B- Main bronchi

This is a typical radiograph of a cat with asthma. Notice how the lung is not as dark, and has a a moth-eaten appearance. This is feline asthma.

Our digital radiography might give you a better view of the moth eaten appearance in a different cat. Click on it to enlarge.

This cat has asthma also, but the radiograph is not typical. The arrow point to the lesion in the lungs.

A different view of the radiograph you see above. You can see the problem area in the lungs at the arrow. Compare it to the other side where the lungs are dark (normal).

We cannot assume that just because a cat is breathing hard it has asthma.
This is what fluid looks like in the thoracic cavity. Notice how little dark lung there is. There are several different causes of this. They include diaphragmatic hernia, heart disease, pleural effusion, FIP, pyothorax and chylorthorax to name some of the more common ones.

Some of the fluid was drained from this thorax. In this case it is called chylorthorax. You can tell by the milky fluid in the syringe.

After draining the dark lung tissue becomes more apparent. There is still a substantial problem, but at least now the lung can expand and the cat can get some air.

Bronchial Wash

Bronchial wash is a secondary diagnostic test.  For this test a small amount of sterile saline is flushed into your cats trachea (windpipe). This saline is retrieved and analyzed for cell type. An excess of a type of white blood cell called an eosinophil could indicate asthma. Eosinophils can also be found in normal cats, so this is not a perfect test.

In addition to analyzing the cells a culture and sensitivy can be performed to look for pathogenic bacteria. It is common to grow bacteria in this culture, so this test is not always helpful. If the bacteria are grown in large amounts, or if a Mycoplasma is present, we will sometimes treat with antibiotics.

Special Tests

Heartworm antibody and antigen tests can also be used to eliminate the possibility of feline heartworm disease.

Fecal

Fecal exam to check for worms ( internal parasites). Many of these replicate or migrate through the lungs, and can cause coughing.

Treatment

Acute- when your cat all of a sudden has a severe problem

100% oxygen

Cats that are having a severe breathing problem, called dyspnea, are placed in 100% oxygen. This calms them down and allows them to get the oxygen they are starving for. We usually do this before we proceed with any diagnostics or treatment.

We can monitor the ability of the lungs to provide oxygen to the red blood cells with our pulse oximeter. This detects the oxygen saturation of the red blood cells. We like to see this in the mid to high 90’s. This is a good way to monitor if our treatment is working.

This cat, under anesthesia to have its teeth cleaned,  has a pulse oximeter reading of 96%- this is excellent. As you can see, our machine also monitors carbon dioxide levels.

Injectible bronchodilators are also used when the respratory problem is severe.

Chronic- for long term control

Earlier in this page we talked about causes of asthma in the cat. Eliminating those causes can be highly beneficial. That would be the first step in controlling chronic asthma whenever possible. In most cases, this is just not feasible. So we need to rely on medication.

  • Salbutamol inhaler

    This has proven to be the most effective treatment for long term control of asthma in cats.

    Asthma-inhaler-2


    Asthma-inhaler

    It is a short acting beta 2 adrenergic receptor agonist, which means it is a bronchdilator. This opens up the breathing passages in the lungs.

    Asthma-inhaler-3

    A special kit is available for cats that has a mask (on the left) to place over your cats face

    Asthma-inhaler-4

    The inhaler is put on the back of the kit and your cat breathes in the medication

  • Prednisolone

    This is cortisone, and it is highly effective in controlling symptoms. It is a life saver for most cats with asthma. Compared to other species, cats are tolerant of this drug. Overuse can cause diabetes mellitus and urinary tract infections, so it needs to be used under our supervision.
    It can be given by injection, pill, or in a liquid form, and should be given on a steady basis.
    Most people use the pill from because of the ability to control the dose- giving extra only when needed, using a low level when the problem seems stable. There is an inhaled version that can be helpful in some cats.

  • Terbutaline

    This is the most common bronchodilator used for this problem. Most cats respond well, which means we can lower  their prednisolone dose.  If all goes well, we might even be able to stop prednisone. It is given as a pill, usually every  12 hours.

  • Cyclosporine

    If the above medications are not working it might be helpful to try this class of drugs.

  • Antibiotics

    We will use antibiotics on occasion, especially if we suspect pneumonia or if prednisolone and Terbutaline are not helping. Common antibiotics are Clavamox and enrofloxacin.

  • Weight reduction

    This is common sense if your cat is obese. We have high fiber diets to help. The two primary ones we recommend are Hills R/D and W/D. There is a significant benefit to the asthma problem when an overweight cat gets to its normal weight.

  • Avoiding allergens

    If you can identify the specific allergen in the environment causing the problem this could be highly beneficial. The problem is in identification. A high quality HEPA air filter could be beneficial.

    Clean any air filters for your house, heater, or air conditioner

  • Food Trial

    Feeding a low molecular weight protein (Hills Z/D and ultra) will be effective if your cat has a food allergy. You have to feed for up to 2 months to know for sure, and you cannot feed any other food or snacks.

Summary

Most cats with asthma are kept well controlled with medication. Be on the alert for subtle breathing patterns that signal the problem could become acute. This needs immediate attention by us. Try to keep stress to a minimum, and make sure your pet is not overweight. This is an all too common problem, and predisposes your pet to other problems besides asthma.

For most cats the prognosis is good for the long term if caught early enough and medication is used consistently.

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Carnaissal Tooth Abscess

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The upper 4th premolar (carnaissal tooth) has two deep roots that must be properly removed, or the abscess will remain, and the tooth will continue to drain under the eye. The tooth and its root are large in comparison to the other teeth, and must be removed in segments.


Drainage Tract

A chronic drainage tract usually is present just under the eye. Sometimes there is an actual hole in the skin, other times there is only swelling or discharge matted to the hair. Most pets resist when you pet them on the muzzle. An odor might be present also.


Drilling Tooth

A high speed drill is needed to cut through the tooth enamel. It is a precision instrument that is powered by our dental unit. The high speed means there is little trauma to the surrounding tissue.


Splitting Tooth

The tooth is split in half with the high speed drill. This allows us to remove each half of the tooth separately, aiding in root removal. We use a dental elevator to remove this tooth just like a retained deciduous tooth. Each half of the tooth is gently elevated out.


Removing Tooth

The split tooth is gently removed with the elevator. This is the most arduous part of the procedure and can take 15 minutes or more to complete. It is important to remove all of the root for the problem to resolve. After removal the opening in the gums is flushed with an antibacterial solution to remove all of the infection.


Healing Process

The hole that remains can be sutured or left to heal on its own. The healing time is within 1-2 days, whether it is sutured or not. The drainage under the eye disappears within a few days also. Antibiotics are usually administered at home for 7 days.

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Mammary Cancer (Breast Tumor)

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These preventable tumors are the most common tumor in female dogs as they age. They do occur in males, but this is a rare occurrence. Up to 50% of these tumors in dogs are malignant. The specific cause of this problem is unknown, although there is a very strong correlation to hormones, especially in the dog. It is an accepted fact, proven over many years, that if you spay (ovariohysterectomy) your dog  prior to its first heat cycle there is a negligible chance your pet will get this cancer. The longer you wait once your pet starts its heat cycle the greater the chance it will get this problem.

Mammary tumors account for 17% of all cat tumors. They are the 3rd most common tumor in cats, after skin and blood cancer. Even though cats get this problem half as often as  dogs, almost all of them are malignant.  Intact females are at highest risk, although it does occur in males on rare occasion. Even though early spaying in the cat does not seem to yield as much protective effect as in the dog,  you can still decrease the incidence of this tumor by up to 60% by spaying early.

Mammary tumors are very common in rats.

Some owners wait so long for medical care that by the time we see them they are as large as the rat.

We have two  short Quicktime movies of surgery using the laser to remove a mammary tumor. They are graphic in nature, and not suitable for all viewers.


Terminology

It is helpful to be exposed to several medical terms that will be used later in this page:

tumor- abnormal tissue growth cancer – malignant tumor
malignant- tumor that spreads to other organs  causing substantial organ failure benign- tumor that does not spread or cause organ failure
mammary or mammae – breast tissue lymphatics- complex of organs that drain excess fluids
lumpectomy- removal of part of the mammary gland simple mastectomy- removal of the entire mammary gland
regional mastectomy- removing the whole affected gland along with other glands unilateral mastectomy- removal of all the glands on the affected side along with underlying tissue and lymphatics.
metastasis- spread of tumor, usually through the bloodstream or lymphatics, to other organs. colostrum- first milk that contains antibodies

Anatomy

In dogs there are 5 sets (varies from 4-6) of mammary glands in a chain, for a total of 10 mammae. From top to bottom they are called:

  • Cranial thoracic
  • Caudal thoracic
  • Cranial abdominal
  • Caudal abdominal
  • Inguinal

From top to bottom you can trace the nipples. How many nipples do you count on this dog?

Nipples even show up on a radiograph. Can you see the three that are apparent on this radiograph?
They are the 3 small and circular white spots- there is one towards the top left, one towards the lower right, and one at the lower left.

 

The inguinal mammary tissue tends to the largest, and produces the most milk. Due to its size this area can look like it has a tumor when in reality it is normal. If you feel an enlargement here one of our doctors should check it to confirm it is nothing more than fat. This is the most common mammae for a tumor to form in the dog.

The upper mammary glands drain towards the auxillary (arm pit) lymph nodes. The inguinal mammary glands drain towards the inguinal (groin) lymph nodes. The middle mammary tissue (caudal thoracic and cranial abdominal) can drain in either direction. You can learn much more about lymph nodes by following this link.

In the cat there are 4 pair of mammary glands. The cranial gland are the most common ones for tumors to occur.

For a little comparative anatomy fun; manatees, and primates only have two mammary glands.

Physiology

Mammary glands are modified sweat glands. They reside in the subcutaneous (SQ) fat, which is the fat just under the skin but above the muscle. The primary function of the mammary glands is to produce milk and hormones.

Milk contains:

  • Water
  • Lactose (the milk carbohydrate)
  • Fat- much higher in some animals than others, usually in the form of tryglycerides.
  • Protein- Also varies quite a bit by species. The primary protein in milk is caled casein.
  • Mineral, vitamins, and enzymes.

Whale and seal milk has 12x as much fat, and 4x as much protein, as cow’s milk. Cow’s milk has less protein and fat than cat and dog milk, which is why orphan kittens and puppies do not do well on it. It takes between 500 and 1000 liters of blood to make 1 liter of milk in the cow.

Numerous hormones are involved with the production of milk:

  • Progesterone
  • Insulin
  • Glucocorticoids (cortisone)
  • Prolactin
  • Estrogen

In the first week of lactation the milk that is produced is called colostrum. This milk contains antibodies to protect kittens and puppies from routine diseases like Distemper and Parvo.

Hormone receptors for estrogen and progesterone are present in the dog. In the cat there are usually progesterone receptors, the estrogen receptors are not very prevalent.

Classification of Mammary Tumors

Mammary tumors can be malignant or benign. In dogs, up to 50% are malignant. In cats, almost all mammary tumors are malignant (adenocarcinomas). Although there are histologic variations on this, these are the main classifications. The more common ones are at the top of each list:

Benign

  • Adenomas
  • Mixed tumors
  • Fibroadenomas
  • Mesenchymal

Malignant

  • Tubular adenocarcinomas
  • Papillary adenocarcinoma
  • Anaplasric carcinoma
  • Sarcomas
  • Solid carcinomas
  • Mixed

Cause

The exact cause of mammary tumors is unknown, although there is a strong correlation to hormones. It has to do with estrogen and progesterone receptors on the tumor. These receptors are present in up to 70% of canine mammary tumors, and 10% of cat tumors. For this reason we tend to stay away from estrogen and progesterone type drugs when treating other diseases.

If your dog is spayed (ovariohysterectomy) before it goes into its first heat cycle, the chances this dog will get breast cancer later in life is virtually nil. A typical female dog will go into heat at 9 months of age, although this varies. If your dog is not spayed until after its first heat cycle the risk of breast cancer can be as high as 8% later in life. Another heat cycle prior to spaying gives a 26% chance of cancer later in life.

Another way to minimize the risk of mammary cancer is to keep your dog at its proper weight.

It is also beneficial to spay a cat early in life. This is especially important in cats because most of their breast tumors are malignant.

Symptoms

The beginning signs of breast cancer can be hard to detect because they are so subtle. Also, mammary tissue tends to hang down hiding any swelling or enlargement.

You should examine your dog or cat weekly while you are playing with it or petting it. Most pets love to have their bellies scratched, which is an ideal time to do your exam.

Run your hands along both chains of mammary tissue from top to bottom feeling for any difference in symmetry. Palpate each gland individually and gently for swelling, discharge, ulceration, hardness, extra warmth, nodules, or discomfort.

Look at each mammary gland, especially each nipple, for any signs of discharge, inflammation, or swelling. Any of the above symptoms are an indication to bring your pet in for us to perform an exam and even run some tests if we think a problem is present. Other symptoms to look for are lameness, swelling of the limbs, or difficulty breathing.

Diagnosis

thorough approach is needed for a correct diagnosis of mammary tumors. In every disease we encounter we follow the tenet’s of the diagnostic approach to ensure that we make an accurate diagnosis, and also so that we do not overlook some of the other diseases that are common in pets .

Diagnosing some cases of mammary tumors is straightforward, especially if the disease has been present for a significant amount of time before a diagnosis is made. Unfortunately, in these cases the disease can be well entrenched, and malignant tumors have had significant time to spread.

  1. Signalment

    This tends to be a disease of middle-aged and older unspayed female dogs and cats. Even though it can occur it is rare in males.

    Some breeds have a higher incidence:

    • Hunting breeds- retrievers, pointers, and spaniels
    • Terriers- Boston, fox, and Airedale
    • Dachshunds
    • Poodles
    • German Shepherds

    Some breeds have a low incidence:

    • Collies
    • Boxers

    Siamese cats  have twice the risk as other cats, and their tumors tend to me more malignant than other cats. Domestic shorthair cats (DSH) have a higher incidence than other cats also.

  2. History

    Due to the location of the breast tissue it is easy for an owner to overlook this problem . Pets with early breast cancer do not show the usual symptoms of disease in general. They are usually active, eating well, maintaining normal weight, and have normal bathroom habits. A small tumor that is growing can easily be present for months before an exam is performed. This adds to the problem and can make treatment more complicated.

    Some owners find a swelling, discharge, or a growth while bathing or petting their dog or cat. Any suspicious area should be checked by one of our doctors to determine if there is a growth, swelling, or just normal breast tissue.

    When the tumor has already spread some pets might have difficulty breathing (dyspnea) due to buildup of the tumor in the lungs, or lameness due to spread of the tumor to the bones. In cats the dyspnea can be due to fluid buildup in the thorax (pleural effusion).

    This cat has a mammary tumor at the nipple. This is the only sign of disease it had, and can easily be missed if you are not observant. This problem was easy to spot once we clipped the hair in preparation for surgery.

    The tumor in this cat is more apparent. Unfortunately, when we see them at this stage they might have already spread since most cat tumors are malignant.

    Intact female dogs can have a false pregnancy 2-4 weeks after their heat cycle that will cause the mammary tissue to swell and mimic a tumor. It is due to the progesterone that is produced during the heat cycle, and the problem will resolve on its own in a few weeks.

    Other diseases that mimic breast cancer include an infection called mastitis, skin tumors, and an inguinal hernia. In cats the inguinal fat pad can be enlarged and mimic a tumor. Foreign bodies like BB’s (not all that uncommon for a cat to be found with a BB when we take an X-ray) feel like tumor nodules.

  3. Physical Exam

    In some cases a swelling or growth is found in the breast tissue during an exam for a different problem, or during a routine wellness exam.

    Nodules might be small and solitary, or the whole mammary chain can be affected. Nodules that are adhered to the skin or underlying tissue, are ulcerated, painful, or swollen tend to be malignant. Nodules that are rapidly increasing in size also tend to be malignant. There might be a discharge from the nipple, and your pet might be running a fever.

    Here are some typical lesions in a cat





    Whenever your pet is placed under anesthesia we perform a thorough exam, including mammary tissue. This is an ideal time because your pet is not moving, it is commonly on its back and we have good access and visualization of the area, and the muscle relaxation allows us to thoroughly palpate small nodules. Your pet can have a malignant tumor and show minimal to no symptoms.

    This dog is under complete general anesthesia just prior to her spay surgery. With the hair clipped away at her abdomen you can see the good access we have to the mammary tissue.

    This enables our doctor to perform a thorough exam of all the mammae
    Enlarged lymph nodes due to spread of  tumor might also be noted. A lymph node can contain the spread of tumor cells and still appear and feel normal. Cats frequently have the spread of their tumor to the lymph nodes.

    One of the typical lymph nodes we will check during an exam are the axillary (arm pit)

    In this picture that cat’s head is to the right, and we are checking the inguinal lymph nodes on the insides of the rear legs.  If a malignant tumor has spread through the lymphatic system it can cause swelling of the rear legs due to blockage of the lymphatic drainage system.

  4. Diagnostic Tests

    Any pet suspected of having a mammary tumor needs routine tests as the first part of the diagnostic process.

    Blood Panel

    A CBC (complete blood count) and biochemistry panel should be run on every dog or cat 8 years of age or more, especially if they have any of the symptoms of mammary disease

    The CBC checks red and white blood cells. We are looking for signs of infection, cancer, anemia, or excess production of red blood cells. If your pet has mammary cancer it might also have inflammation or a secondary infection. We might get a clue of this from the CBC.

    This cat might have an inflammation or infection as evidenced by the increase in the white blood cells. This is called leukocytosis. If the physical exam findings are consistent with an infection then we might put this cat on antibiotics before initiating any other treatment at the moment.

    The next part of the blood panel is called the chem or biochemistry panel. It checks the internal organs, along with electrolytes and specific physiologic tests like blood sugar.

    Dogs and cats with mammary tumors tend to be older, so Geriatric Diseases are more prevalent. Since surgery is usually a major part of treatment we need to make sure the internal organs are ready for anesthesia. This is particularly true of kidney and liver disease. Some pets with mammary cancer will have a high calcium level on this panel.

    The same cat as above has a normal biochemistry panel

    In some cases we might run a clotting panel looking for any signs of a disease called disseminated intravascular coagulation (DIC). This can occur when there is an inflammatory carcinoma.

    Urinalysis

    A normal specific gravity in a dog should be around 1.025 or higher, cats should be higher than 1.035. There should be no or minimal protein, glucose, WBC’s, or bacteria, as a general rule.

    Cytology

    In this test we insert a tiny needle with attached syringe in the mammary tissue. It is a tiny pin prick, and is the same kind of needle we use to give vaccines.  Some cells are aspirated into the syringe and then gently pressed on to a microscope slide.

    The pathologist looks at these cells to give us an idea of what we might be up against.

    In some cases we use this test, especially if it is difficult to differentiate inflammation from an actual tumor. Its also gives us an idea of just how malignant or non-malignant the tumor is, so we can adjust our surgery accordingly. In cats we assume the tumor is malignant and usually skip this test and go right into surgery.

    Even though it can be a  useful test, it only looks at a small portion of the mammary tissue. So it is used only as ancillary information prior to surgery and not to make a final diagnosis. Also, multiple tumor types might be present, and you can make the wrong interpretation with just this test.

    Aspiration of a local lymph node can also be helpful to detect evidence of any spread of a tumor. In cases of extensive mammary involvement, usually the whole chain, we might completely remove the lymph node that drains that area. This gives the pathologist much more tissue to work with to ascertain if there has been a spread of the tumor.

    In cats that have fluid buildup in their thorax we can submit this fluid for cytology also.

    Radiography

    Radiography (X-Rays) are a very important test prior to surgery because up to 50% of the dogs with malignant breast cancer have spread of the disease to the lungs at the time of their exam. We need to confirm that there is no spread (metastasis) of the tumor to the lungs or else surgery might not be indicated. We take 3 different views of the chest to determine if the lungs are clean.

    In this chest radiograph we have placed black arrows at some of the white and round areas that are the spread of the tumor in the lungs. Compare it to the normal dog radiograph below if you need to.

    Normal dog chest radiograph

    This is what a mammary tumor under the skin looks like on a radiograph. It is that round white object on the bottom.

    Some cats will show signs of difficulty breathing. It can be subtle, so it behooves you to spend some time every day observing your pet for any changes that indicate a problem. This cat has fluid that  has built up in its lungs.

    The first one is from a normal cat. Notice the normal black lung area.

    In this radiograph from a problem cat there is fluid throughout the thorax and you cannot see normal black lungs. The lungs have collapsed due to the fluid in the thorax. The only lung tissue you see is the slightly dark leaf-shaped structure towards the top of the thorax.

    After oxygen therapy for stabilization we drained some fluid off the thorax. This caused an immediate improvement in breathing. A radiograph taken soon afterwards shows improvement as evidenced by the increase in the normal amount of black lungs visualized. When this fluid appears due to the spread of a malignant tumor from a mammary gland the prognosis is poor.

    In some cases a radiograph of the bones will show spread of cancer. If a radiograph is taken of the abdomen some malignant cancers will show an enlarged sublumbar lymph node. Ultrasound is beneficial here in assessing local lymph nodes and abdominal spread from a malignant mammary tumor.

    This abdominal radiograph shows the location of where the sublumbar lymph node is normally located. It is not apparent in this view, so it is not enlarged.  The K stands for kidney and the B stands for urinary bladder. Ultrasound tends to be a more accurate way to assess abdominal lymph node enlargement when compared to radiography.

  5. Response to Therapy

    One of the tenets of the diagnostic process is whether or not a treatment that is instituted actually corrects the problem. Surgery is the main form of treatment, so response to treatment does not apply as much as to other diseases that are more medical in nature and treated with drugs.

Treatment

Note: This section has links to two graphic movies during surgery to remove mammary cancer. They are not suitable for all viewers.

The treatment of choice for mammary tumors is surgery. Chemotherapy, radiation therapy, nor hormonal therapy have any proven benefit.

It is routine to spay (OVH) an intact female dog prior to or during surgery to remove an affected mammary gland. Even though at this usually late date it will not prevent more tumors from appearing, it will prevent uterine infection (pyometra) and uterine cancer, and might even prevent hormone influence on existing tumors.

If the gland is infected we might use antibiotics to reduce the swelling and inflammation. This will allow us to see the margins of the tumor more readily during surgery.

When your pet is relaxed under anesthesia, and the hair is clipped away prior to surgery, we will examine the mammary glands again. It is not uncommon to discover a small tumor that was missed during the routine exam.

Once our diagnosis and ancillary tests are complete we will remove the mass surgically. Depending on the location, size, duration, species, and physiologic status of your pet, we might do a lumpectomy or remove part or all of the chain. In extensive cases we might have to remove one chain of tissue in a first procedure, then the other chain several weeks later when the first chain has healed. Since cats usually get malignant tumors it is common to remove the whole chain on the affected side.

In all these surgeries we remove a wide margin of tissue to ensure we removed all of the tumor. In all cases our goal is to remove all of the tumor and get what are called “clean edges” by the pathologist. This means there is no microscopic signs of tumor cells in the tissue submitted for analysis. This makes for a much better prognosis.

This is a typical mammary tumor noted in a cat

After wide surgical incision this is the opening prior to suturing

What the suture site looks like when we are finished. The rubber tube is called a penrose drain tube.
It is used to decrease swelling during healing, and is removed in 3-5 days. When the sutures are removed in 10-14 days their is minimal scar and its hard to tell surgery was even performed

Since cats frequently get malignant tumors we commonly remove the whole chain of mammary tissue on the affected side. We might also remove the closest lymph node to look for metastasis.

We routinely use our laser for this surgery. This dramatically minimizes post operative bruising, discomfort and swelling. We can’t emphasize enough how important the use of the laser is in this surgery. Prior to our laser these dogs and cats would have extensive bruising and swelling of the sensitive mammary tissue. We would place many sutures under the skin to prevent fluid buildup and discomfort. We no longer need to with the laser. Dogs and cats that have this surgery, even when a radical surgery is performed, routinely go home the same day and have minimal discomfort. When laser is used with routine pain medication your pet will usually be eating and resume normal activity within 12-24 hours.

When we remove the mammary tissue on one whole chain there is a long incision. With the use of the laser and routine surgical and post surgical pain medication these cats recover rapidly from surgery.

Click on the link below to see a laser lumpectomy surgery on a cat. Notice how little bleeding there is when the laser is used.

Lumpectomy

This next cat has more gland involvement and requires more surgery. Notice how diseased the tissue appears and the lack of bleeding when using the laser. As the surgery progresses you can see milk coming from the gland.

Click here to learn more about the laser and how it is used in many types of surgeries at our hospital.

Post surgery treatment

Diseased mammary tissue that is removed during surgery is submitted for histopathic analysis. The pathologist will determine the type of tumor and will also stage it. Stages usually go from 0 – 3.

  • Stage 0- Tumor cells are limited to the ducts within the mammary tissue
  • Stage I- Tumor cells are in the ducts and the supportive or framework tissue of the mammae (called stroma)
  • Stage II- Tumor cells are in the blood vessels, lymphatic tissue, or regional lymph node
  • Stage III- Tumor cells have spread through the body- usually lungs or bones

Chemotherapy is used when we cannot remove all of the tumor of if your pet has inflammatory carcinoma.  Chemotherapy for mammary cancer tends to be unrewarding. Some of the drugs we use, which should be under the direction of a veterinary oncologist, include:

Dogs

  • Fluorouracil
  • Doxorubicin
  • Cyclophosphamide
  • Cisplatin
  • Carboplatin

Cats

  • Doxorubicin
  • Carboplatin
  • Mitoxantrone
  • Cyclophosphamide

Tamoxifen, a product commonly used for human breast cancer, is ineffective and has the potential for serious side effects in dogs.

In some dogs and cats the tumor is not resectable. This occurs in inflammatory carcinomas. In these cases we used what is called palliative therapy. We attempt to keep them comfortable with antibiotics, pain medication, fluids, assist feeding, good nutrition, and lots of TLC.

Prognosis

If your pet’s tumor is benign and completely removed, then it will be cured of the disease. Benign tumors can appear in other glands though when only a nodule is removed and the gland is left intact.

If the tumor is malignant then it is hard to predict due to the variable nature of the malignancy. Low grade malignancies can be cured with surgery. Those tumors with a higher stage of malignancy or ulceration can recur and spread within the first year of surgery. Some of the factors that influence prognosis are:

  • Tumor size- tumors smaller than 2-5 cm have the best prognosis for malignant tumors.

If the tumor is smaller than 2-3 cm many pets will live up to 3 years.
If the tumor is larger than 2-3 cm most pets will live for 6 months

  • Tumor histology- Sarcomas, carcinomasarcomas, and malignant mixed tumors have a poorer prognosis than carcinomasadenocarcinomas. Inflammatory carcinomas have a very bad prognosis.
  • Tumors classifed in histologic stage II or III carry a worse prognosis.

Cats with malignant tumors usually do not survive more than a year. Their tumors grow rapidly and spread to the lungs early, usually before a pet owner is aware and brings them in for diagnosis and treatment. Prognosis for a cat depends on 5 factors:

Tumor size

If there is spread to the lymph nodes

Histologic grade:

Stage I- > 24 months

Stage II- 12-24 months

Stage III- 4-12 months

Stave IV- 1 month

Invasion of the lymphatics that drain the gland

Siames cat has a poorer prognosis than domestic cats

This is the report on the cat with the nipple that was inflamed. We showed you the picture of this tumor earlier when we talked about how easy it is to miss some of these tumors.

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Squamous Cell Carcinoma (SCC)

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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.

To help prevent his serious problem from happening in your cat there are three things you can do:

Have us show you how to do an oral exam on your pet during an office call. Our In Home Exam page has more information on performing this exam.

Come in for a yearly Wellness Exam. For older pets, which should examine them every 6 months.

Have your pet’s teeth cleaned, whether it is without anesthesia, called a Non Anesthetic Dental, or under anesthesia. In each of these we perform a complete oral exam.

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 from their original location 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.

Symptoms

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.

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.

A close up view shows how extensive it is

The radiograph of this cat shows how the cancer has invaded the jaw. There are two areas to note on this view of the lower jaw. The right jaw bone (on the left in the picture) is affected. It has a moth-eaten appearance that can be visualized by comparing it to the left side of the 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, so that lymph node 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 by a physical exam 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 more 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 cute 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, under general anesthesia and ready for surgery, 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. 

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.

We also use the Companion Laser after surgery to minimize swelling and discomfort. In this picture it is being used after a spay (OVH) surgery. 

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.

The laser is very specific in how it performs surgery, and is specifically calibrated for each procedure.

You can see how it checks its circuits and is calibrated in this video

SSC can occur in other locations, and in other species besides cats. Dogs can also get SCC, although we don’t see it in the mouth and ears as often as we do in cats.

This limping dog has SCC at its toe (arrow). You can see how the bone is being destroyed. Phalanx #2 and #3 are involved.

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)

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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

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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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Femoral Head Ostectomy (FHO)

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When the neck of the femur is fractured it needs surgical repair. There is a surgical procedure, that was developed many decades ago, that removes the non-functional head, and allows the body to form a false joint. This procedure is called a Femoral Head Ostectomy (FHO). Ostectomy means removal, so the head of the femur, where the ball joint is located, is completely removed.

We also use this procedure when there is a hip dislocation (called a subluxation) and the hip will not stay in the socket, even when we put it back in and put on a special bandage called an Ehmer sling. We also use this surgery for pets with hip dysplasia that will not be undergoing the more extensive hip replacement surgery called a Total Hip.

These are the radiographs of a young German Shepherd that was hit by a car. It was brought to us for a limping problem on the left rear leg. A thorough physical and orthopedic exam revealed some swelling at the left knee. This is a VD (venture-dorsal) view of the pelvis.

Do you see the problem?

The wing of the ileum and the acetabulum are fractured. You can also see that the neck of the femur has been fractured. Compare the problem area above in the red circle to the other side. 

This purple line like gives you a conceptual idea of where the neck of the femur will be cut during the FHO surgery. The exact angle during the procedure is different, and is customized for each bone.

This fracture is 3 week old, and there is swelling and scar tissue around the fracture that is not apparent on this radiograph. Also, this is a large breed dog with large muscles and tendons surrounding the fracture. In a difficult case like this, especially in a young dog that has a long life ahead, we have an orthopedic specialist come to our hospital to perform the surgery. He has special equipment, and over 45 years of experience, to make this a successful surgery with a pain free and active dog that is not limping for the rest of its left.

Before any surgery is performed, our surgeon Dr. Paul Cechner, consults with the owner to go over all of the options. This includes post operative care, which is an important part to make sure adequate healing occurs.

Long before surgery we perform a blood panel and a chest radiograph to make sure there are no other problems from the initial trauma that are not apparent on physical exam. This is important to know before surgery to minimize the risk of anesthesia, and to make sure all problems are corrected. Our patients do not talk to us, and they have high pain thresholds compared to us humanoids, so they don’t always show symptoms and we need to be thorough. We do not want any surprises on the day of surgery.

It is important to take a chest radiograph prior to surgery to make sure the heart and lungs look normal

Once the consultation was performed we put this dog on a pain and anti-inflammatory NSAID called Rimadyl until the day of surgery. Our patient was brought into the hospital the night before surgery and intravenous fluids were started and a pain patch was applied. On the day of surgery another examination was performed by one of our veterinarians to make sure everything is OK. At this point the surgery is a go and our surgeon prepares.

Our patient is anesthetized and the leg is shaved outside of our surgery room

While our patient’s leg is shaved our surgeon starts the scrubbing process with a surgical hand scrub to make sure this is an aseptic procedure

Our patient is brought into surgery, and before anything else is done, is hooked up to our anesthetic monitor and the IV fluid pump (at the top of this picture) is set for the correct amount of fluids to be given during the procedure. These fluids are critical to minimize anesthetic risk. 

Once our patient is stable and under the proper plane of anesthesia, our surgical assistant goes through the multi step process to scrub the leg. This is a crucial step to minimize the risk of infection after the surgery, so we are thorough and methodical in our approach to this part of the procedure. As you view the following pictures you will realize that preparation is a key part of this surgery.

The first step is to tape the leg up in this position

The first scrub of the leg occurs with the leg in this position

He continues scrubbing the leg after our surgeon does an initial draping

Once our surgeon is satisfied with the initial surgical scrub,s he does his own final scrub with a special antiseptic

It is called DuraPrep

It is applied directly over the area of the incision

After the DuraPrep our surgeon drapes the leg with it still hanging. In the background is our anesthetist monitoring anesthesia.

The top of the leg is wrapped in sterile aluminum foil and the tape is cut to bring the leg down

This is the position of the leg during the surgery

The foil is wrapped with a special sterile tape

The appearance of the foot before the final draping

Another drape without a hole is put over the surgical field

Our surgeon makes a custom opening in the drape specific for this surgery

He checks the exact location of where his incision will be before proceeding any further

The next step in the preparation involves and aseptic barrier called Ioban

It is adhered right to the skin where the incision will be

The surgical preparation is now complete and our surgeon is ready to make the skin incision to start the surgery

His sterile bone cutting tool is now opened up

He palpates the landmark for the skin incision 

Let the surgery begin!

Once through the skin the next layer encountered is the subcutaneous (under the skin) layer, sometimes abbreviated as SQ.

The surgical approach goes between several important muscles and tendons in order to gain access to the joint where the fracture is located. These include the biceps femoris muscle, the tensor fascia latae muscle, the superficial gluteal muscle, the deep gluteal muscle, and the vastus lateralis muscle. The muscles and tendons are not cut in order to gain this access to the joint. Careful dissection is performed in this area to preserve the normal anatomy, and not interfere with important nerves and blood vessels  This is one of the most difficult parts of the procedure, and where the experience of our surgeon comes into play.

After much careful dissection Dr. Cechner has the head of the femur exposed in the center of this photo. It is difficult to see because it is covered in scar tissue.  On the left is the special oscillating saw that will cut through the neck of the femur. The opening is small, so our surgical assistant on the right is using a retractor for better visualization

The oscillating saw gives a quick and precise cut with minimal bone trauma

The appearance of the head of the femur just before the cut is complete

A special rongeur is used to smooth off the bone incision

Now the long process of suturing everything back together begins

The postoperative radiograph

Our patient stayed overnight with pain injections administered that were in addition to the pain patch. He went home the next day with antibiotics and oral pain medications The skin sutures were removed in 14 days. After several weeks of confinement, and several weeks of moderate use, he is doing great! Our thanks to Dr. Paul Cechner for doing such a great job.

If you would like to learn much more about how we do surgery at the Long Beach Animal Hospital, including pre-anesthetic testing, anesthesia, and surgical concepts, please visit our Surgical Services web page.

 

 

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Retained Deciduous Teeth

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It is not uncommon for us to encounter dogs with retained baby teeth. If they are still present at 6 months of age when your pet is spayed or neutered, we will remove them.

This dog is 8 months old and has a retained deciduous (D) tooth behind its erupting adult lower right canine (C) tooth. It is interfering with the eruption process of the normal canine tooth and will be removed

The instrument used to remove this tooth is called an elevator. The tooth is gently removed by rotating the elevator around the base of the tooth where it meets the gum line. This is to ensure complete removal of the tooth, including its root. Each tooth takes 5-10 minutes of gentle elevating to remove.

 

When the tooth is removed a small hole remains in the gum. The hole is usually so small that it heals rapidly and rarely requires suturing the gum. The healing time is the same whether the gum is sutured or not.

 

Here is the culprit after removal, notice how deep the root goes. The left 2/3 of this tooth (to the left of the arrow) is the root.

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