LBAH Informational Articles

Masai Mara 2007 Birds

Masai Mara Trip October 2007

Birds

Kenya has well over a thousand species of birds. We would awaken in the morning to their calls and see them all day long in the air and on the ground.

This page has a few of the more interesting ones. At the end of the page we have a sequence of a martial eagle, the biggest in Africa, flying off its nest. This page also has a phenomonal set of photos where an eagle attacked a vulture in mid-air.

One of our goals is to teach photographers how to capture the colors some of these birds exhibit. Another goal is to practice shooting birds in flight, which is quite a challenge
due to their speed and erratic movements. In addition to lots of practice, our equipment made a big difference here.


This is a yellow billed stork taken at Rokero camp just after lunch. He is looking for his lunch, and today’s menu happens to have a special on frogs.

Secretary bird. It eats snakes and eats small mammals, large insects, lizards, and snakes. You oftentimes find them on the ground, although occasionally you will see them in a tree.

Lappet faced vulture. It is the largest vulture in Africa, and is the first one to arrive at the kill and open the carrion for other vultures.

A beautiful bird called a striped kingfisher

A colorful bird found throughout the Mara is this lilac-breasted roller

Its lots of fun trying to capture them in mid-flight when they dart all around

Male ostrich on the lookout for a mate

A female ostrich on the lookout for a free ride to visit a friend in Nairobi

A martial eagle, the largest in Africa, putting on a show for us. This is where the Canon 1D Mark III camera came in handy.

Vultures are good to practice your shooting technique on flying birds. They glide in slowly and do not have many erratic movements. This paid off big time for Peter when you see the next sequence of photos.

No biggie here, just a few photos of vultures gliding through the air so people can get a feel of shooting them in flight

Lots of practice, and being in the right place at the right time sometimes yields phenomenal results. Notice the bird in the background at the right of this lapet-faced vulture?
Can you guess what it is? At first glance we assumed it was a vulture also.

Its an tawny eagle

And it is literally attacking the vulture because the vulture got too close to its nest

Different day, different tawny, eating a breakfast of rabbit in the tree right above us

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Predators

As you can imagine there are many predators in the Mara.We saw and have photos of hyena, mongoose, bat-eared fox, jackals, serval, and the rare caracal. I even had a mongoose visit my tent one night as he pitter pattered around the sides. I did not know what it was at first, and when I looked out the screen he was looking right at me. After 3 seconds he took off, and I never heard back from him again.

This page will link to the 3 primary predators we encountered. Within each section I have picked out the photos that show some of their more active behavior. I want to depict them as we saw them in their natural environment, and something more than you will see in a zoo.

Cheetah

Lion

This is the same lion in the Disney movie African Cats. They call him Fang in the movie, we called him Snaggletooth.

Leopard

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Ol Seki Camp

Ol Seki was even more luxurious than Rekero. This is because it is a permanent camp and does not have to be taken down yearly. At Ol Seki you can go on long walks and you can go on night drives because you are outside the Mara National Reserve.

Just like in Rekero, the food is great, the staff are great, the accomodations are very comfortable, and the wildlife is literally just outside your door at night.


Sue, Matthew, and the awesome guides that ran Ol Seki

Sue’s son designed Ol Seki. It had wooden floors and a beautiful library that overlooked the surrounding area.

 

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Rekero Camp

Here are a few photos of this wonderful camp at the Talek river. It is run by Gerard Beaton and his very competent (but funny talking) manger Rob Stower. If you plan on a trip at the Mara we highlly recommend it.

The food is great, the staff are great, the accomodations are very comfortable, and the wildlife
is literally just outside your door at night. This camp is taken down for 2 months every year, then reassembled for the next season.

Rokero is right inside the Masai Mara National Reserve, so you are not allowed to go on walks or
night drives. The abundance of wildlife you see during the day makes up for this.


Gerard’s wife and Kate, another camp assistant

Rob (Mr. Rugby) Stower

Two of the many guards that watched over the camp at night and escorted us around

Our camp was located on the Talek river

A common area where we met and had tea time at precisely 4 PM every day. This is an important ritual carried over from the British days.

 

Different view of above. Lots of conversations, naps, eating, and drinking occurred in this room day and night.
Off to the right, out of the picture, is the dining area.

Our comfortable rooms. On the pink table at the left our early morning wakeup person would leave us tea or coffee at 6 AM.

Wash basin in front of the shower

Any time you needed a shower they would bring
hot water

The loo

Lunch was outside every afternoon. We saw wildebeest
and leopard crossing the river one afternoon.

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Heart Diseases And Their Treatment

  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……

    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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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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Causes and Symptoms of Heart Disease

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Asthma

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

 

The upper 4th premolar (carnaissal tooth) has 2 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)

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. This area 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. 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.

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

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

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.

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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Fracture Jaw in a Cat

It is not uncommon for a cat to break its jaw due to a traumatic incident; usually falling from a height or being hit by a car. The lower jaw (the mandible) usually fractures right in the middle of the chin which is very painful and renders the pet unable to use its jaw to eat. Fortunately for most cats, they heal very well when the jaw is wired back together. Now if only they can remember not to run across the street again……

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

Symptoms and Diagnosis

In almost all cases of jaw fracture the diagnosis is obvious. The pet is drooling, the jaw hangs down, and it is unable to eat. There are frequently other signs of trauma present somewhere on the body.

Palpation of the jaw (under anesthesia) reveals the extent of the problem. The location of this fracture is called the symphysis of the mandible.

Treatment

The two halves of the lower jaw (the mandible) are wired back together with stainless steel wire. The wire is kept in place for approximately one month, then the cat is anesthetized again and the wire removed. Most cats begin eating within 1-2 days of the repair, and only rarely do we have to place a feeding tube in so they can ingest adequate calories. If there are no other problems almost all cats heal completely.

A special stainless steel wire is placed around the lower jaw. To be anchored properly, and to stay in place until healing is complete, the wire must pass through the underside of the jaw.

The surgeon then aligns the 2 fractured pieces and gently tightens the wire. When finished the wire passes under the tongue but over the lower jaw.

The ends of the wire pass out through the skin under the jaw. The wire is pushed up against the skin so it does not interfere or snag on things.

This radiograph gives an inside view of the wire.

The roof of the mouth (the hard palate) is bruised because this cat was hit by a car. Fortunately the hard palate was not fractured, so no further treatment was needed.

The tongue was severely bruised also. This is the type of lesion, that when added to the fractured jaw, can prevent a cat from eating. Luckily the bruised tongue healed within a few days and this cat started eating soon. If not we would have put a feeding tube in.

Jaw fractures can be quite painful, so it is common for us to use pain medication.

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Feeding Tubes

In comparison to people, feeding tubes in animals are not routinely used in terminal cases to prolong life. They are used to help an animal get over a temporary problem and return to good health.

Most species of animal can go many days without eating. This is not true for cats, especially when they are sick. Several days of not eating (anorexia) can have serious consequences in cats and lead to failure of important organs like the liver.

In addition to cats we use feeding tubes in our practice for turtles and tortoises that are not eating.

Causes of Lack of appetite

Internal organ diseases like hepatic lipidosis, infections, FeLV, and fevers, along with anatomical problems like a broken jaw can all prevent a cat from taking in adequate nutrition. In addition, all of these diseases increase caloric needs for healing to occur, so a lack of appetite in a diseased cat is an important problem to address.

The yellow discoloration to this cats gums is called icterus, more commonly know as jaundice. In this specific case the icterus is caused by liver disease because this cat has hepatic lipidosis. Feeding tubes are commonly used in these cats because they have stopped eating.


Short Term Treatment Options

Several options are available to give adequate nutrition to cats that are not eating. Many times they begin eating after we rehydrate them with intravenous fluids, especially if they have kidney disease. Sometimes we also need to assist feed them with special foods that are easy to administer and digest. Some cats will even start eating after we give them valium intravenously. Cats that have sugar diabetes (diabetes mellitus) might begin eating after we control their blood sugar level with insulin. Cats that are in pain from serious injury like a broken jaw might start eating when we give them pain medication.

This liquid diet called Clinicare is often used to provide both fluid and nutrition on a short term basis. It can be given orally or through a tube.

Another food used to provide short term nutrition is called A/D. It is also used for long term nutritional support in some cases. It can also be given orally by just putting it in your pets mouth. It can also be given through a tube when some water is added to it.


Medium Term Treatment Options

A nasogastric tube is an option that sometimes works well for several days. This tube is passed through the nostrils and into the esophagus. It is taped and sutured in place. It has the advantage of easy placement and maintenance. The main problem is that the small diameter of the tube that is used only allows a liquid diet (CliniCare). To give an adequate amount of calories on a long term basis with this liquid diet would mean giving a volume of liquid that is far too much for the digestive system to handle, and the cat will usually vomit.

Another medium term treatment option is tube feeding. In this technique we fill a syringe with A/D and attach a small rubber feeding tube to the end. We gently pass this tube into your pets esophagus and give it the full amount of food that is in the tube. It has the advantage of using a food source (A/D) that is more solid than a liquid diet (CliniCare), so your pet receives more of its needed calories. It also has the advantage of minimal discomfort since no tube is left in for long periods of time. Some cats will begin eating on their own after only 1 or 2 feedings with this technique.

Long Term Treatment Options

  • PEG Tube

    A very effective solution to long term feeding is a PEG tube. PEG stands for Percutaneous EndoGastric. It consists of a tube that passes from the inside of the stomach, through the abdominal body wall to the outside. It allows the long term use of food that will give adequate nutrition. Its first disadvantage is difficult placement. It is usually put in with a special instrument like an endoscope, or is placed surgically during an exploratory surgery of the abdomen. Both methods require general anesthesia. In addition, a further disadvantage is the potential for infection in the abdomen at the site the tube passes out of the stomach.

    In this picture you can visualize the PEG tube that is exiting from the stomach after an exploratory surgery.

  • Esophagotomy Tube

    In terms of ease of placement, cost, and effectiveness, one of the best options for long term feeding is an esophagotomy tube. It does not require specialized equipment or exploratory surgery, and can usually be placed with sedation only. Serious complications are rare, and usually consist of regurgitation of food if too much is given too rapidly, especially in the first few days of feeding. This problem tends to go away by itself.

    The esophagotomy tube passes from the left side of the neck into the far end of the esophagus. The tube is measured to ensure that the proper length is passed, and that the tube does not go into the stomach. This picture shows the measurement of the tube.

    This is the appearance of the tube immediately after insertion and suturing to the skin.

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    When it is bandaged only the tip where you will insert the food is visible.

    An x-ray reveals the path of the tube. The arrows on top outline the tube that is outside of the neck and under the bandage and along the back. The arrows on the bottom are the feeding tube as it passes inside the esophagus from left to right. As planned, it goes partway down the esophagus and does not enter the stomach. The white structure just below and to the right of the tube in the esophagus is the heart. The tube never touches the heart because it stays in the esophagus.

    Here is another view. Click on it for larger size.

    tuberad

Feeding Technique

A food that is routinely fed through a feeding tube for long term maintenance is called A/D. We have a handout that gives you detailed information on this food. We will let you know how much to give and if we want any supplements added. You usually need to add a little water to it to so that it can flow through the feeding tube.

If a PEG tube has been put in then the food you administer goes directly into the stomach. When food is given through the esophagotomy tube it partially fills the esophagus temporarily until it flows into the stomach. In both cases give the feeding mixture slowly and usually at room temperature or slightly warmed.

You will be feeding several times per day throughout the day. After the feeding you need to flush the tube with a small amount of warm water. If it becomes clogged in spite of flushing, place a small amount of cola or papaya juice in the tube until it dissolves the clotted food.

One of our nurses will give you detailed instruction in how to use one of these tubes before your pet leaves the hospital. If you have any difficulty with this tube we are here to help you, so please let us know if you need assistance after you return home. We would like to check your pet and the tube on a weekly basis until it is removed.

The amount of time the feeding tube stays in varies from weeks to months. Only when your pet is eating well and putting on weight will we remove it. An added advantage to the esophagotomy tube over the PEG tube is the ease of removal. On occasion the PEG tube can cause an intestinal blockage when removed because the tip of the tub remains in the stomach after removal and must pass through the intestines to be eliminated.

The overwhelming majority of cats respond positively to long term tube feeding. If your pet consistently vomits then we will put it on some medication to minimize this usually temporary problem.

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