Category: Cats

Feline Infectious Peritonitis (FIP)

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FIP is one of the most mysterious diseases a wild or domestic cat can get. Cheetahs are particularly susceptible to this disease because of their lack of genetic diversity. FIP is fatal, luckily it is relatively rare nowadays. It is seen more often in cats less than 2 years of age and older than 10 years of age. Multiple cat households, along with cats that spend time outdoors, are most susceptible. The virus that causes this disease is spread by respiratory secretions and feces. Litter that is contaminated with the virus is easily trapped on a cats fur, which is ultimately swallowed when the cat grooms. Cats infected with FeLV also are more at risk of developing this disease.

FIP is the subject of considerable controversy regarding diagnosis and treatment. This is partially due to the environmental situation that cats are placed in that causes undue stress on their immune systems, along with the complicated and variable immune response they develop when potentially faced with this virus. Like many cat diseases, FIP mimics other cat diseases, so a diagnosis in many cases does not come easily, especially in what is called the “dry” form. This page has short QuickTime movies on a cats with symptoms that could be the result of FIP.

This page contains graphic photos of a necropsy (autopsy) towards the end of the page. 

Cause

FIP is caused by a coronavirus, that has mutated from a harmless intestinal virus of cats called the feline enteric coronavirus (FECV). It is not known why the virus mutates from the harmless FECV (it can cause a mild intestinal upset) to the pathogenic FIP. Risk factors for this disease are multiple cat households, the presence of normal cats that shed coronavirus, age, immune status, and the development of FIP susceptible cats (including certain breeds and bloodlines) in the general cat population. The continual infection and reinfection of cats with coronavirus in multiple cat households increases the chance of an individual cat developing FIP.

Any cat infected with a corona virus has the potential of developing FIP, in fact recent studies suggest up to 10% of cats infected with the corona virus may develop FIP. To give you some perspective on the current situation, 30% of household cats and up to 90% of cattery cats carry the coronavirus. Multiple cat households might be more susceptible due to increased stress, crowding, poor sanitation, parasites, and other diseases like the FeLV and the FIV. Cats can spread the coronavirus in their nasal and oral secretions, along with the feces. Even though the virus can remain infective in the environment (contaminated feeding utensils, etc.), it is easily destroyed by routine disinfectants. This virus poses no health risk for people.

Pathogenesis

Within 24 hours of ingestion the virus spreads from the tonsils to the intestines. Within 2 weeks it has spread to the large intestine, intestinal lymph nodes, and the liver. From there it can spread to any other body organ. Cats that do not produce a full antibody response to the virus will end up with fluid buildup within body cavities, usually the chest or abdomen. Cats that develop a full immune response to the virus do not get this disease, although they can harbor a latent version of the virus for a period of time. They are immune, but carry the pathogenic version of the coronavirus, so they can potentially spread it to other cats. If they become immunocompromised for some reason (stress, drugs, crowding, parasites, other disease like kidney disease ) their infection can be reactivated.

This disease has two major manifestations. The first is called the “dry form”. In the dry form the white blood cells are involved, and cause an inflammatory reaction to the internal organs. These organs do not function normally because of this inflammation, and eventually will fail as the disease progresses. The dry form of FIP develops as a result of only a partial immune response to the mutated virus.

The other manifestation of this disease is called the “wet form”, which is where the original name of “peritonitis” (inflammation of the lining of the abdominal cavity) came from. It is called this because fluid accumulates in the abdomen or the chest. The fluid that appears in the wet form is straw colored to yellow in appearance, and has a relatively high protein content. The fluid originates from small blood vessels that have been affected by the immune systems response to the virus. This immune response damages these blood vessels, causing them to leak fluid into the abdominal cavity usually, or thoracic cavity less often. The wet form of FIP develops as a result of a failed immune response to the mutated virus. Cats that already have FeLV are more susceptible to the FIP virus. It has been found that Persian, Abyssinian, Himalayan, Bengal, Rex, Ragdoll, and Birman cats may have an increased susceptibility to the FIP virus.

Symptoms

Initially there are no or minimal symptoms after exposure. Some cats might show mild upper respiratory signs (sneezing) or diarrhea, but are so mild that they can go unnoticed. When serious symptoms do appear, the signs might be sudden in the younger cats, or more gradual in older cats. Cats that have dry form have vague symptoms that come and go, and can affect many different systems in the body. They might be lethargic, have poor appetites,weight loss and look ill.

Common organs involved are the eyes, central nervous system (brain and spinal cord), and internal organs like the liver and kidney. Other symptoms could include seizures, paralysis, behavior changes, poor vision, increased sensitivity to touch, and urinary incontinence. Another clue to dry FIP is a cat with an ongoing fever. It might wax and wane, and usually does not respond to antibiotics.

Since many different organs can be involved with the dry form, the symptoms we see with this form of FIP can mimic other common diseases of cats, like hyperthyroidismliver diseasesugar diabetes and kidney disease. Other diseases like inflammatory bowel disease, cancer, and toxoplasmosis might also have similar symptoms. Pets with the wet form of the disease may have breathing difficulty or distended abdomens, in addition to some of the symptoms of the “dry form”. The onset of these symptoms is faster than the gradual symptoms noted in the dry form.

The wet form of FIP is much easier to diagnose than the dry form. The virus can also infect the brain or spinal cord. This form of the disease can sometimes be diagnosed by an eye exam. Changes can be noted in the back of the eye, especially the retina.

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

Cat with Neurologic symptoms

Diagnosis

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

Physical Exam

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

Blood Panel

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

This is the blood report from our in-house laboratory showing an increase of Total Protein and Globulin (hyperglobulinemia) in an FIP positive cat

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

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

Fluid Analysis

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

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

The report from the clinical pathologist on fluid that his highly suspicious of FIP

Radiography

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

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

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

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

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

Ultrasound

Ultrasound gives us additional information on the internal organs. It augments what we see radiographically, and is an important diagnostic modality in many animal diseases since they cannot talk to us and tell us where there is a problem. Our ultrasounds are performed by a radiologist, a specialist in performing ultrasounds.

This is what ascites looks like during an ultrasound

The ultrasound gave us additional information we do not normally obtain from radiography. An enlarged mesenteric lymph node, in a cat with other indications of FIP, does not verify the diagnosis, but makes it very likely.

Antibody Test

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

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

DNA Test (PCR)

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

This is what the test result for PCR looks like

Histopathology

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

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

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

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

Treatment

There is no treatment that will cure this disease and cats with confirmed cases of FIP usually succumb within a few months or are euthanized due to their condition. Over the years many different treatments have been attempted to alleviate symptoms of this disease. Some of them seem to work for variable periods of time, so they are worth trying in some cases. These include antibiotics, antinflammatories, immune system stimulators, and vitamins. Since it is difficult to confirm the presence of this disease, especially in the dry form, it is worth the effort to treat your cat symptomatically. Unfortunately, the long term outcome is poor.

Several antiviral medications have been tried but do not appear to alter the course of the disease. A medication called Polyprenyl Immunostimulant has shown potential experimentally for the dry form.  It has been used to treat herpes virus. More work needs to be done to make sure it works and does not cause side effects. Work on this treatment is being done by Alfred M Legendre, DVM, of the University of Tennessee. You can find these treatments in our section on FeLV, since both diseases are treating the symptoms of the virus and not the actual virus. The caveats in treating FeLV also apply to FIP.

Controlling the Spread

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

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Feline Leukemia Virus (FeLV)

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

Vaccines have dramatically reduced the number of FeLV cases we have seen over the years, almost to the point of it being non existent in our area.

Cause

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

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

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


Stages

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

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

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

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

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

Symptoms

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

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

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

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

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

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

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

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

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

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

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

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

Testing Recommendations

Testing for FeLV is our first line of defense.

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

Their recommendations are summarized as follows:

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

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


Testing Procedure

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

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

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

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

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

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

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

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

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

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

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

The three different type of positive results that are possible:

FeLV Positive

FeLV and FIV Positive

FIV Positive

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

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

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

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

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

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

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

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

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

Treatment

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

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

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

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

Some of the more common treatments include:

Antibiotics

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

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

Immune Stimulators

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

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

Cortisone

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

Vitamins

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

Fluids

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

Red Blood Cell Stimulators

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

Blood Transfusions

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

Appetite Stimulants

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

Anabolic Steroids

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

TLC

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

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

FeLV Vaccine

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

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

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

Prevention

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

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

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Squamous Cell Carcinoma (SCC)

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

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

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

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

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

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

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

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

Graphic photos later on this page.

Oral Squamous Cell Carcinoma

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

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

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

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

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

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

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

A close up view shows how extensive it is

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

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

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

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

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

Skin Squamous Cell Carcinoma

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

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

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

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

Diagnosis

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

Tumors

Infections

  • Cryptococcosis
  • Blastomycosis
  • Actinomycosis

Dental Lesions

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

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

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

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

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

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

Treatment

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Additional Treatment Regimens

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

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

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

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

Prevention

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

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

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Mast Cell Tumor

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

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

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

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

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

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

Physiology

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

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

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

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

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

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

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

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

 Tumor Behavior

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

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

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

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

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

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

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

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

Cause

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

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

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

Diagnosis

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

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

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

1. Signalment

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

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

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

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

 2. History

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

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

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

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

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

Above the vulva

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

For curiousity sake this is the same dog immediately after surgery

On the skin of the rear leg

Another close up of a MCT on the side

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

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

3. Physical Exam

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

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

o   Submandibular

o   Pre-scapular

o   Axillary

o   Inguinal

o   Popliteal

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

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

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

4. Diagnostic Tests

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

DESCRIPTION:

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

MICROSCOPIC FINDINGS:

Spleen consistent with normal or hyperplastic lymphoid tissue

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

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

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

Surgical Treatment (surgery pictures in this section)

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

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

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

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

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

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

 

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

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

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

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

Tissue Analysis and Prognosis

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

SOURCE– 5 cm skin biopsy of mass on left flank

DESCRIPTION

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

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

PROGNOSIS– Fair to guarded

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Medical Treatment

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

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

  • Lomustine
  • Masitinib
  • Palladia
  • Vinblastine
  • Torcerinib

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

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

Additional Therapy

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

Long Term Care

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

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

Feline Mast Cell Tumor

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

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

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

Cutaneous Form

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

Visceral Form

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

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

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

Treatment

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

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

Prognosis

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

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

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

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

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

Cancer Specialists

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

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

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

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

Name: Leslie

location: Anaheim, CA

Dear Long Beach Animal Hospital,

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

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

Take care, Leslie and Bijou

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Femoral Head Ostectomy (FHO)

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

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

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

Do you see the problem?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

It is called DuraPrep

It is applied directly over the area of the incision

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

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

This is the position of the leg during the surgery

The foil is wrapped with a special sterile tape

The appearance of the foot before the final draping

Another drape without a hole is put over the surgical field

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

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

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

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

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

His sterile bone cutting tool is now opened up

He palpates the landmark for the skin incision 

Let the surgery begin!

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

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

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

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

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

A special rongeur is used to smooth off the bone incision

Now the long process of suturing everything back together begins

The postoperative radiograph

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

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

 

 

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Ear Cleaning

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One of the most important things you can do to keep your pet’s ears clean and healthy is to clean them periodically, especially if they have been prone to infection. This page will show you the proper technique using a medium sized dog as an example. The technique for a cat is similar, the only major difference is in restraint. No matter which species you are restraining, pick a room that is quiet and free of small children. Please let one of our nurses give you an actual demonstration of this technique to develop your confidence.

Before we institute any cleaning of problem ears it is important to make a diagnosis. Not every case of ear infection is caused by ear mites, as many people are prone to think. Ear infections are commonly caused by bacterial infections, hypothyroidism (low thyroid), and allergies. We have found a consistent cause of chronic ear problems and infections is due to a food allergy, which is why we recommend Hill’s z/d, the gold standard for this type of food.

Canine Restraint

Depending on its size, put your dog on a table so that it is approximately chest high. Gently hug your pet under its neck with one of your arms, and put the other hand on the back of its head if necessary. Be patient, yet persistent. If your dog is small you can use the cat restraint technique.

Hugging your pet with your left hand under its chin gives you control and flexibility as to how much restraint is needed.

Feline Restraint

Wrapping your cat with a towel is a good way to restrain it for ear cleaning. In essence you will be wrapping it like a burrito. For cats in general the less restraint the better- let the towel do the work.

Put a large towel on a table and put your cat towards the front end of this towel.

Bring each side of the towel over the cat and leave only the head and tail to stick out

Bring the back, unfolded section of the towel over the front just up to the back of your cat’s head.

Finish the “burrito” by wrapping the towel under each side of your cat. The only thing sticking out of the towel at this point is the head.

Hug your cat gently to you with one hand and you will have your other hand free. Besides cleaning ears this restraint technique enables you to administer oral or topical medication.


Cleaning

Never put anything in your pet’s ear canal without proper restraint. As a general rule you should clean the ears by letting the cleaning solution bring the infection and discharge to the outside of the canal to be wiped away. You should not put Q-tips into your pets ears unless we tell you to and you have been shown the proper technique, and your pet is adequately restrained. Q-tips can damage the sensitive tissue that lines the ear canal. Also, an ear drum can easily be ruptured by placing objects in the ear canal, especially if the ear has an infection.

This is a typical picture of what might be encountered in an ear that needs cleaning.

The first thing to do is use a gauze to wipe away discharge that is on the surface.

Gently pull up on the ear and partially fill the ear with the cleaning solution. By straightening out the ear you allow the cleaning solution to flow down the ear canal to where the infection and debris are located.

After the canal had been partially filled massage the base of the ear canal very gently. Most pets find this part soothing.

Let your pet shake its head if it wants to. Then use a gauze to soak up the fluid that comes out of the ear.


Instill several drops of the actual medication we prescribe after the cleaning solution is out of the ear and the ear is relatively free of discharge. Most pets do fine with daily cleaning and medicating, your doctor will let you know if it should be done more or less frequently than daily.

Now is the time to reward the cleaner and cleanee for a job well done! If you think that was tough, how would you like to restrain this pet and clean its ears? The hugging under the chin technique doesn’t always work on a 300 pound tiger!

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Cancer

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The scientific word for cancer is neoplasia, meaning new growth. In reality, it is an abnormal growth of cells that interferes with an organ’s ability to function, resulting in a degree of failure in that organ. Some of these abnormal cells break off from the organ and spread to other organs in the body. This process is called metastasis, and is the hallmark of malignant cancer.

Cancer it is not one disease, has many different causes, and can affect every organ. This makes it quite a challenge to diagnose and treat. Even though the cause is not known in many cases, we do know of major factors that predispose pets to getting cancer. You will learn about this on this page regarding squamous cell carcinoma (SCC) in white cats that are exposed to the sun.

A major predisposing factor is dogs, cats and rabbits that are not neutered and spayed when they are young.  Their chances of getting breast, testicular, and prostate cancer increase significantly when they are not altered at an early age. The following pages have detailed information on this:

Dog Spay

Dog Neuter

Cat Spay

Cat Neuter

Rabbit Neuter

Rabbit Spay

We tend to see cancer more commonly in our geriatric patients.

This page has links to some of the more common cancer’s we see in animals. Click on any photo to enlarge it.


Dogs and Cats

Intestine

Kidney

Liver

Lymph node

Mammary (breast)

Mast cell

Spleen (hemangiosarcoma)

Squamous cell carcinoma (SCC)

Ferrets

Adrenal disease

Insulinoma

Liver

Rodents

Mammary (breast)

Ovarian

Reptiles

Tegu oral tumor

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Hemangiosarcoma

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Spleen Disease (Hemangiosarcoma, Hematoma)

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

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

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

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

Graphic surgical photos are on this page

Nomenclature

We will use some medical terms regarding the spleen:

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

Spleen Anatomy

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

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

A normal spleen in a cat

A normal spleen in a  small dog

A normal spleen in a medium sized dog

A swollen spleen in a medium sized dog

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

Physiology

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

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

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

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

Diseases

Splenomegaly

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

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

This spleen has splenomegaly in addition to numerous nodules

Splenic Torsion

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

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

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

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

Examination of a pet with splenic torsion might reveal:

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

A blood panel might reveal:

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

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

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

Splenic Cancer

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

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

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

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

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

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

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

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

Hematoma

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

Other causes

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

This spleen has a laceration

Diagnosis

Signalment

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

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

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

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

History

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

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

Physical Exam

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

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

Diagnostic Tests

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

Radiography

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

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

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The red circle delineates the enlarged spleen.

L.I. – Large Intestine

Pr- Prostate

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Blood Panel

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

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

Fluid Analysis

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

Ultrasonography

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

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

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

The lines demarcate the margins of this spleen

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

A typical ultrasound report on a dog with a cancerous spleen

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

RV- Right ventricle

RA- Right atrium

Cytology

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

ECG (Electrocardiogram)

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

Definitive Diagnosis

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

Histopathology

Treatment

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

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

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

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

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

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

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

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

Splenectomy

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

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

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

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

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OVH-rabbit-2

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

This machine monitors:

Temperature

Heart Rate

Heart rhythm

Oxygen saturation

Carbon dioxide level

Respiratory rate

Surgery-Monitor

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Ancillary Treatment

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

Post Surgical Treatment

Prognosis

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

Splenic Hematoma – good

Splenic Torsion – good

Hemangiosarcoma – guarded to poor.

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Lymph Node Diseases

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The lymph nodes are part of the lymphatic system. They have several important functions and are good indicators of disease. During a physical exam the external ones can be palpated to determine if they are enlarged. The medical term for this is lymphadenopathy.

Causes

Lymph nodes can enlarge due to several reasons:

  • Inflammation

    A reaction to a foreign body might cause this.

  • Infection

    Bacterial, viral, or fungal infections can cause them to enlarge. This enlargement might be a sign that they are performing their job as expected. When the infection subsides the lymph node should return to normal size.

  • Cancer

    The most common cancer that causes this problem is called lymphoma (also know as lymphosarcoma)

Examination

Internal Lymph Nodes

Numerous lymph nodes exist within the thoracic and abdominal cavities. They can not be palpated easily, and their enlargement does not show up on routine blood samples. They might be seen on radiographs or ultrasound if they are significantly enlarged. They can be found when performing an exploratory surgery.

This radiograph of the chest shows the heart and lungs clearly. The lower arrow points to the location of the sternal lymph node. It is not visible in this dog because it is normal. The top arrow points to a round, white structure. It is a tumor nodule that has spread from cancer elsewhere in body.

This radiograph of the abdomen shows the liver and stomach clearly. The lower arrow points to the general location of the mesenteric lymph node. The top arrow points to the location of the sublumbar lymph node. Neither one is visible.

The scalpel blade is pointing to the mesenteric lymph node. This node is found at the center of the small intestine loops. This one is enlarged because this cat has kidney cancer, which has spread to the mesenteric node.

Here is another enlarged mesenteric lymph node from a cat with intestinal cancer called lymphosarcoma.

External Lymph Nodes

Mammals have numerous external lymph nodes (also called peripheral lymph nodes) that can be palpated during a physical examination. This is of great advantage because we can easily feel if they are enlarged without having to rely on diagnostic tests. Reptiles and birds do not have external lymph nodes.

Five external lymph nodes are routinely palpated during a physical exam. All of them are paired, which is another advantage because we can compare one to another and notice subtle changes in size:

  1. Submandibular

    They are located in the neck area near the angle of the jaw. They lay right next to the salivary glands, so it is important to palpate the correct structure.

  2. Prescapular

    Located just in front of the shoulders. Follow the arm up to the point of the shoulder to find them.

  3. Axillary

    Found on each side of the chest in the armpit area. They tend to be small, and are more forward then most people realize.

  4. Inguinal

    Found on the abdomen towards the inside of each rear leg. There is significant fat in this area, so they might be difficult to find, even if enlarged. Also, there is mammary tissue in the area that can easily feel like an enlarged lymph node if the mammary tissue has an infection or cancer.

  5. Popliteal

    Found on each rear leg on the opposite side of the knee. They are relatively superficial and easy to feel.

We will gladly teach you how to palpate these lymph nodes whenever you bring your pet in for a physical  exam. These are internal organs so they are always palpated in a gentle manner. You might want to palpate them on a weekly basis at home. If you think they are enlarged bring your pet in for an exam so we can determine if there is a problem.

Diagnosis

Fine Needle aspiration

This test is a relatively simple way to obtain a significant amount of information from an enlarged lymph node. In this test we use a small needle (similar to the one we use to give vaccines) and gently insert it into the enlarged lymph node. We aspirate some of the lymph node material and put it on a microscope slide.

This ferret has a very large right submandibular lymph node. Do you see the needle on the left side of the picture that we are using to obtain the aspirate sample?

The aspirated material is put on a microscope slide for analysis by a pathologist. They will put special stains on the material and carefully scrutinize it under the microscope.

This is a typical report obtained when the pathologist reads the sample on the microscope slide. It is from a labrador with 2 enlarged lymph nodes.

The fine needle aspirate test is not infallible at finding a problem. When the needle is inserted it is put in only by feel. It is possible for the lymph node to have a problem area that the needle missed. Also, we are giving the pathologist only a very small sample to read. It can be difficult to determine the health of the whole lymph node when only a small sample is taken.

Due to these limitations the pathologist sometimes can not say for certain what caused the lymph node to enlarge. If it comes back inconclusive then we might keep the lymph node under close observation. If there are other changes in the rest of the physical exam, or laboratory data indicates there might be a significant problem, we will remove the whole lymph node and submit it for analysis.

If the fine needle aspirate report comes back that cancer is suspected we will remove the lymph node, no matter what the other laboratory tests indicate.

Biopsy

The most accurate way to determine if a lymph node is seriously diseased is to remove the whole node and submit it for analysis. It gives us significantly more information than the fine needle aspirate. It requires anesthesia and an small incision in the skin. We routinely use our laser for skin incisions for its great ability to minimize bleeding, swelling, and post-operative pain.

This picture shows a popliteal lymph node in Dr. P’s hands. He is getting ready to make an incision in the skin over the lymph node with the laser.

This is the inflamed popliteal lymph node as it appears under the skin. It will be completely removed.

Here it is after complete removal. It is the size of a large pea.

The report on this dog gave us a diagnosis of valley fever, which is a fungal infection. You don’t have to read through all of the medical mumbo jumbo to get to the valley fever diagnosis at the end. In the last paragraph you can see that special stains were needed to make the final diagnosis. These special stains are not easily performed on a fine needle aspirate.

This report of cancer came back on a Labrador Retriever. This is the same dog that had the fine needle aspirate report above.

This cat has an enlarged popliteal lymph node. We used the laser in this case also.

We use the laser to make an incision in the skin because of the lasers ability to minimize bleeding.

The inflamed lymph node is easily visualized. Note the lack of blood in the surgery site.

The anatomy of this lymph node is not normal, an indication that it is diseased.

Because of the unique qualities of the laser we are able to perform this surgery with a very small incision.

Treatment

Inflamed lymph nodes are treated with an anti-inflammatory like cortisone. Pets with bacterial or fungal infections are treated with antibiotics or anti-fungal medications. There is no specific treatment for a lymph node that is enlarged due to a viral infection. If cancer is the cause of the enlargement it will be treated with surgery, chemotherapy, radiation, or a combination of all of these.

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Addison’s Disease (hypoadrenocorticism)

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This disease of the adrenal glands of dogs (it’s very rare in cats) involves inadequate hormone levels of cortisol (cortisone) and electrolytes (sodium and potassium). This unusual disease can show a vast array of different symptoms, symptoms that mimic other diseases. There is even a version of this disease called “atypical”, which adds to the complexity. Because there can be such a variety of symptoms, Addison’s disease is sometimes known as the great pretender or great imitator. In any dog that is ill, our veterinarians need to keep this disease in mind.

Addison’s is named after a physician in 1849’s who discovered this disease. President John Kennedy suffered from the human version of this disease.

Addison’s disease is the opposite of another problem with the adrenal glands called Cushing’s Disease (hyperadrenocorticism). In Addison’s there is not enough cortisol, in Cushing’s, there is too much cortisol.

We have an interesting page on adrenal disease in ferrets, which causes different symptoms than in dogs and cats.

Nomenclature

Several medical terms and abbreviations relate directly to Addison’s:

glucocorticoids – Cortisol tachypnea-increased respiratory rate
exogenous cortisone– supplemental cortisone by mouth or injection bradycardia-abnormaly slow heart rate
catabolic steroid– cortisol and its equivalent polyuria– excess urinating
anabolic steroid– opposite of catabolic, testosterone is the most common one polydipsia– excess drinking
hyperkalemia- high potassium (K) level in the bloodstream PU/PD– polyuria and polydipsia
tachycardia -abnormally fast heart rate mineralcorticoid-hormone that affects sodium and potassium
hypoglycemia– low blood glucose (sugar) level iatrogenic– caused by something a person does as opposed to happening naturally.
hyponatremia- low sodium (Na) in the bloodstream ACTH– adrenocorticotrophic hormone
atrophy-an  organ that is smaller than it should be adrenomegaly– enlarged adrenal gland
anemia– low red blood cells microcardia- small heart
cortisol– Cortisone made by the adrenal glands  azotemia– elevated BUN and creatinine

Adrenal Gland Anatomy

The adrenal glands are paired organs that lay right in front of the kidneys on each side. They are quite small, and measure only a few millimeters in length. This small size is not an indication of their importance though. Even though they are small, the cortisol (cortisone) they secrete, along with their other functions, have great significance to normal physiology.

The arrows point to the paired adrenal glands in front of each kidney. The extensive blood supply to the kidneys and adrenal glands is apparent. In the diagram they are easy to see. They are not so easy to see during ultrasound or exploratory surgery because normally they are small and buried in fat. They do not show up on an X-ray unless they are calcified or much larger than normal.

This is a picture of an enlarged adrenal gland (arrow) that is buried in fat near the kidney (K). It is from a ferret that has an adrenal gland tumor, so the adrenal gland is inflamed and easily visualized. This is not necessarily the case in dogs and cats that have adrenal gland tumors.

The internal architecture of the adrenal gland is made up of several distinct zones.

Cortex

The cortex (outer shell) of the adrenal gland is made up of 3 anatomical parts:

Zona Glomerulosa

This is the outer layer of the adrenal gland. This section secretes the mineralcorticoid aldosterone. Aldosterone is vital to proper sodium and potassium regulation. Aldosterone has a role in maintaining  blood pressure.

Zona Fasciculata

This is the next layer as you go inward, and produces the glucocorticoid cortisol. The cells in this area are the ones that cause Cushing’s when they secrete cortisol in excess.

Zona Reticularis

As we continue inward we come across this section that secretes the sex hormones known as androgens (male sex hormones), estrogen (female sex hormones), and sex steroids. These are usually secreted in such small amounts as to be of no major significance in healthy animals. The gonads in dog and cats secrete most of the sex hormones.

Medulla

This consists of the very center of the adrenal gland. It secretes hormones called catecholamines. The two important ones are epinephrine (adrenaline) and norepinephrine.

Physiology

The tiny adrenal glands have a profound influence on many internal organs. The hormones they secrete work in unison with other hormones and internal organs, particularly the liver, and have an enormous effect on physiology. These hormones interact with many other hormones that have the opposite effect, usually in some type of feedback mechanism that is monitored by the brain. This interaction is complex, so only a summary of adrenal hormone physiology is presented.

The adrenal glands secrete several important hormones, most of which are synthesized from cholesterol. We will explain 3 of them; cortisol, aldosterone, and epinephrine:

Cortisol

Cortisol maintains a normal blood glucose level, facilitates metabolism of fat, and supports the vascular and nervous systems. It affects the skeletal muscles, the red blood cell production system, the immune system, and the kidneys. Obviously, it is a very important hormone, and necessary for life.

It is considered a “catabolic steroid”. This means it takes amino acids from the skeletal muscles and, and with help from the liver, converts them to glycogen, the storage form of glucose. These functions are the exact opposite of “anabolic steroids”, the drugs that weight lifters take to increase muscle mass. The end result of this is an increase in the level of glucose in the bloodstream. The hormone called insulin has the opposite effect on blood glucose, adding to the complexity of this system. You can learn more about insulin by going to our diabetes mellitus page.

The level of cortisol in the bloodstream continually fluctuates as physiologic needs vary. Surgery, infection, stress, fever, and hypoglycemia (low blood sugar) will cause cortisol to increase. This continual fluctuation adds to the difficulty of diagnosing any disease involving cortisol (Addison’s and Cushing’s), because the amount of cortisol in the bloodstream is so variable.  A test taken at one moment in time might have different results if taken later.

To control the level of cortisol the hypothalamus and pituitary gland in the brain secrete chemicals into the bloodstream called releasing factors. In the case of the adrenal glands , the hypothalamus secretes a hormone called corticotropin releasing hormone (CRH). This hormone goes to the pituitary gland and stimulates it to release a hormone called adrenocorticotrophic hormone (ACTH). It is the amount of ACTH circulating in the blood stream that tells the adrenal glands (specifically, the cells at the zona fasciculata) how much cortisol to secrete. There is a negative feedback loop that allows the hypothalamus and pituitary gland to refine precisely how much cortisol circulates in the bloodstream. The more cortisol secreted by the adrenal glands, the less CRH and ACTH secreted. This allows the body to precisely refine the level of cortisol, and to change the level rapidly due to changing physiologic needs.

This negative feedback mechanism is a highly profound adaptation to evolutionary pressures, and is the basis for our survival as a species. Without this, life as we know it, would not exist for us and many species on this planet.

Numerous organ systems are affected by cortisol:

Musculoskeletal

Cardiovascular

Skin

Renal

Gastrointestinal

Immune

Mineralcorticoids

Aldosterone is the principal mineralcorticoid secreted by the adrenal glands. This hormone is secreted as a response from the kidneys when fluid volume in the bloodstream is decreasing. It involves other hormones called renin and angiotensin. The end result is an increase in sodium in the bloodstream, with a corresponding increase in blood volume and blood pressure. This increase in blood volume and pressure is because  sodium  pulls fluid from the intestinal tract, and the area around each cell called the extracellular fluid, into the bloodstream.

This hormone also interacts with and affects potassium levels. To further complicate the picture, ACTH also has an affect here, just like it does with cortisol.

Epinephrine (Adrenaline)

This compound, technically called a neurotransmitter, also has hormone-like properties. It is a very powerful chemical that affects all organ systems. It acts very rapidly, with effects remaining only for a short period of time. It is the primary reason the body has the ability to respond to an emergency. This physiologic mechanism is also known as the “flight or fight” response.

Upon stimulation of the central nervous system (ex.-fear or pain), the adrenal medulla is stimulated to secrete epinephrine into the bloodstream. We are all familiar with what happens next. The pupils dilate, the heart rate and blood pressure increase, and the palms get sweaty. Internally, the body is increasing the blood glucose level, the breathing passages are opened up, more red blood cells are secreted into the circulation, blood is shunted away from the skin and other internal organs, and blood flow is increased to the brain and skeletal muscles. All of this has the effect of bringing the brain and skeletal muscles extra glucose and oxygen, and accounts for the extra boost of awareness and energy we all feel at this time. For such a small set of organs it is apparent that the paired adrenal glands have a very important role in normal health.

Pathophysiology

When the disease affects the part of the adrenals that secrete cortisol (the zona fasiculata) a vast array of different symptoms can occur. This is because of the profound effects cortisol has on almost all body systems.

When the disease affects the part of the adrenals that secrete aldosterone (the zona glomerulosa), then electrolytes like sodium (Na) and Potassium (K) are affected.

The overwhelming majority of the adrenal cortex must be affected before it secretes inadequate amounts of cortisol and aldosterone and before any symptoms are noted.

There are 3 forms of this disease:

Primary Hypoadrenocorticism

 This classic form of the disease is due to a lack of both mineralcorticoids and glucocorticoids. The zona fasiculata and the zona glomerulosa are both involved. This means the problem is at the adrenal gland itself.

Causes:

Immune system destruction of the adrenal gland due to autoantibodies is the most common cause

Medication to treat Cushing’s disease (mitotane or trilostane)

Infection

Coagulation disease

Cancer

Loss of blood supply to the adrenal gland (an infarction)

Secondary Hypoadrenocorticism 

This more unusual form of the disease occurs when the zona fasiculata only is involved. This means the problem is at the pituitary and not at the adrenal gland, therefore only cortisol production is compromised and the electrolytes sodium and potassium are not affected.

Causes:

Abruptly stopping oral or injection cortisone that has been administered for a period of time (exogenous cortisone)

Congenital defects of the pituitary gland

Cancer or trauma to the hypothalamus

Atypical

This includes all of the dogs classified as secondary, so only cortisol is involved. In these dogs electrolytes are normal,  just like in secondary hypoadrenocorticism. What makes this atypical is that fact that many dogs might change to primary during the course of the disease. Only then will the electrolytes  be involved.  This can make treatment difficult, because a pet that is being treated successfully for secondary might need to be treated for primary at some point. This emphasizes the need for close monitoring with blood panels and exams at least every 6 months.

Diagnosis

Signalment

Usually found in female dogs that are middle aged or less. It is more commonly found in dogs that are not spayed (ovariohysterectomy).  Atypical Addison’s tends to occur more in the older dog. Certain breeds get this disease more often than others:

  • Great Danes
  • Standard Poodles
  • Bearded collies
  • Portugese water dogs
  • Rottweilers
  • Wheaten Terriers
  • West Highland White Terriers (Westies)

History

Symptoms are quite variable, and can come and go over months.  As a result, it is easy to miss this disease or get it confused with other diseases that have the same symptoms. Symptoms might be mild, or they might be life threatening, and can be found in many other diseases.

In some cases, a pet has been ill in the past, and treated with fluids with a successful outcome, and now the problem has returned. A blood panel in this situation might show a kidney problem due to dehydration, which is why the fluids helped. If this is a recurring problem, Addison’s should be tested for.

Typical symptoms might include:

  • lethargy
  • inappetence
  • weight loss
  • diarrhea or dark stools
  • vomiting
  • shaking
  • dehydration
  • shock
  • collapse
  • drinking and urinating more than usual (PU/PD)
  • abdominal pain
  • seizures if severely low blood sugar is present

Physical Exam

Just like the symptoms above, the physical exam of a dog with this disease can be quite variable. Typical exam findings we might encounter include:

  • depression
  • pale gums
  • tacky gums
  • panting
  • hair loss
  • weak pulse
  • increased heart rate (tachycardia) if shock
  • decreased heart rate (bradycardia) if potassium is high
  • increased respiratory rate (tachypnea)
  • low body temperature
  • painful abdomen upon palpation

Diagnostic Tests

Radiography

X-rays might be helpful in diagnosis, although they are not the primary way this disease is diagnosed. On a radiograph we might find a small heart and liver due to dehydration and shock. On rare occasions megaesophagus (enlarged and non-functional esophagus) might be present. None of these symptoms are diagnostic of Addison’s by themselves, since numerous other diseases can cause these symptoms.

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The heart is the white object in the center of this radiograph. Compared to the heart in the radiograph below it is small, which might indicate dehydration due to Addison’s. 

The adrenal glands do not show up on an abdominal radiograph unless they are calcified or extremely enlarged, which would be more indicative of Cushing’s and not Addison’s.

Electrocardiogram (ECG)

If the potassium is high enough (hyperkalemia) the heart rate might be slow (bradycardia) and there might be changes in the electrocardiogram. There are other causes of hyperkalemia, so this is not diagnostic for Addison’s, it is a clue that Addison’s might be present. The most common cause we see for hyperkalemia is a cat that cannot urinate in the obstructed version of FLUTD (Feline Lower Urinary Tract Disease).

Below is a normal ECG strip for 4 beats of the heart. Below the strip is an enlargement of one beat.

If hyperkalemia is significant, changes to the ECG might include:

  • slow heart rate (the 4 beats below might only be 2-3 beats)
  • absent P waves
  • widening (prolonged) QRS complex
  • Shorter (decreased amplitude) R wave

EKG

Ultrasonography

Ultrasonography would usually show small adrenal glands, although a dog can have Addison’s and have normal adrenal glands on ultrasound. The adrenal glands in Addison’s are tiny, and can be difficult to find in some cases.

OLYMPUS DIGITAL CAMERAThis is a normal right adrenal gland enlarged for easier viewing. It is marked by the + signs.

Tuffy3

This is a small left adrenal gland like we might find in Addison’s. It is the whitish area in the center towards the top with the dark area in the center. It takes an experienced ultrasonographer to find a small adrenal gland.

Blood Panel

Blood work ( chemistry and complete blood count) is a crucial component for detection of this disease. Common abnormalities might include one or more of these findings:

  • anemia (low red blood cells)
  • increased eosinophils and lymphocytes
  • low blood sugar (hypoglycemia)
  • azotemia (high BUN and creatinine)
  • hypercalemia (high calcium)
  • hyperkalemia (high potassium)
  • hyponatremia (low sodium)
  • hypochloremia (low chloride)
  • increased liver enzymes (ALT)
  • increased alkaline phosphotase (ALP)
  • hypoalbuminemia (low albumin)
  • hypercholesterolemia (high cholesterol)
  • low ratio of sodium (Na) to potassium (K). If the ratio is less than 27:1, and the history and symptoms are consistent with this disease, then a high index of suspicion is appropriate.

Cortisol decreases the blood flow (also called GFR-glomerular filtration rate) to the kidneys. This will result in an decrease in the amount of water and waste products filtered by the kidneys. On the blood panel this might show up as kidney disease, when in reality it is Addison’s. Our kidney disease page has more details.

Each of the following blood panels was taken from a dog with Addison’s. They are all different, a testimony to how variable this disease can appear on a blood panel. When coupled with the wide variety of symptoms, that can wax and wane, a diagnosis of this disease is not black and white.

 In this first blood panel, the only abnormal finding of significance is the low RBC, HGB, and HCT. This means the pet has anemia.

Notice how these tests are mostly normal, although this dog has Addison’s

BuddyHansonBlood

In this dog with Addison’s, the chloride, sodium, and glucose  are low. The Na/K ratio is OK.

Tuffy2

This dog with Addison’s has numerous abnormalities, this time including a low Na/K ratio

Special Tests

Cortisol level

In this test a baseline cortisol level is run by taking a blood sample.  If the baseline cortisol is over 2 mcg/dl (micrograms per deciliter) then the dog does not have Addison’s. There is no need to go any further since Addison’s is not involved at this point. If the baseline cortisol is less than 2 mcg/dl then we will do the ACTH stimulation test.

ACTH Stimulation test

Diagnosis is confirmed with an ACTH (adrenocorticotrophic hormone) stimulation test. This test is also used to help diagnosis the opposite problem of Addison’s disease, which is called Cushing’s disease.

ACTHgel

Once the baseline blood cortisol is obtained we give an injection of a specific amount of ACTH. One hour later we take another blood sample to check if the cortisol level has changed. We get the reports from the lab usually the next day.

If the baseline cortisol is less than 2 mcg/dl, and it does not increase on the blood sample taken one hour later after we have injected ACTH, then the disease is confirmed.

Addison's-4

Akita’s and Shiba inu’s sometimes have elevated potassium levels on blood tests. This can be very confusing when a patient has symptoms that suggest Addison’s disease. The ACTH Stimulation test will let us know if they have Addison’s.

An occasional dog will be presented with symptoms consistent with Addison’s, including abnormal sodium and potassium levels. These dogs might have Whipworms and not Addison’s. Again, the ACTH Stimulation test will let us know if they are Addisonian. We have a page on internal parasites that includes Whipworms.

Treatment

Acute Phase

In the acute phase, dogs are presented collapsed and in a state of shock and hypothermia. They need shock doses of intravenous fluids and injectable cortisone (dexamethasone) along with warmth. If the hyperkalemia is causing bradycardia, the IV fluids usually suffice.  If not, insulin needs to be administered. If hypoglycemia is present, dextrose is added to the IV fluids.

Chronic Phase- Most dogs are presented in this phase

For low cortisol we use prednisone orally at a relatively low but consistent dose. Any pet with chronic Addison’s needs to have this dose increased when there is a stress like fireworks, going to the groomer or veterinarian, or anything in general that causes extra stress.

We will test the blood every 6 months at the least to make sure there are no serious side effects to this use of cortisone. For the majority of dogs, there are no side effects, and the drug is mandatory for treatment of this disease. The symptoms of the disease, and their potentially life threatening nature, far outweigh side effects when used under our supervision.

Prednisone

Prednisone and prednisone are tried and true drugs that have been used to treat this disease for many decades

For an imbalance in electrolytes we use one of two drugs, although the injectable version is much more convenient and very effective:

Percorten-V (DOCP)Percorten-V works extremely well for most dogs and allows them to lead a normal quality of life. This injectable medication is given every 25 days for the majority of dogs. We will test the electrolyte levels with a blood panel early in the course of treatment to monitor Na and K levels and adjust the timetable accordingly. We will then test the blood at least every 6 months.

Percorten

Harmony is drawing up Buddy’s Percorten

Addisons-HarmonyInjection1

Buddy comes in every 25 days on the dot, and after his pinprick injection (we use a 25 gauge needle so it is jut a pinprick) he is good to go for another 25 days.

Addisons-HarmonyInjection2

Florinef – It does have some cortisone properties, and in some cases a dog does not need prednisone when on this drug. This does not apply to stressful situations, and additional medication in the form of prednisone tablets is always needed.This oral medication has fallen out of favor as a treatment because it has to be given daily, and some dogs develop a resistance wherein the dose has to be increased.

Florinel

The pills are small and easily given

Prognosis

This is a hormone disease, which means it is part of a highly tuned and refined mechanism that is in constant state of change. Vigilant monitoring is of essence for a successful outcome. We have numerous dogs at our hospital currently being treated successfully with prednisone and Percorten-V over many years. These dogs are leading a normal life, and you would have no idea they have a serious hormone disease when you see their owners bring them into our hospital or take them for a walk.

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