Feline Internal Medicine
Feline hyperthyroidism was first described as a spontaneous disease in 1979. Shortly thereafter it became recognized as the most common endocrine disorder of the cat. The elevated circulating levels of the thyroid hormones thyroxine (T4) and triiodothyronine (T3) that occur in hyperthyroidism result in a multisystemic disease.
The most commonly recognized signs of hyperthyroidism are weight loss, hyperactivity, and an increased appetite. An increased water consumption and urination are other common signs of feline hyperthyroidism that are thought to result from an increased blood flow to the kidneys. Gastrointestinal signs are common in hyperthyroidism. Intermittent vomiting and diarrhea are frequently noted. Cardiovascular signs including an increased heart rate, arrhythmias and congestive heart failure, are common in cats with hyperthyroidism. Most cats with hyperthyroidism develop a reversible form of heart disease with congestive heart failure developing in 10 to 15% of these cats. Apathetic hyperthyroidism represents an unusual form of hyperthyroidism that occurs in approximately 10% of cats with hyperthyroidism. In these cats, the typical signs of hyperactivity and increased appetite are replaced by depression and inappetance. Weight loss may progress at an enhanced rate in these cats. In addition to these nonspecific signs, a majority of hyperthyroid cats will have an enlarged thyroid gland.
Feline hyperthyroidism occurs in middle-aged to old cats with no breed or sex predilection. The clinical signs of hyperthyroidism may vary from extremely mild (in some cases no clinical signs are recognizable) to severe. The multisystemic effects of hyperthyroidism result in signs that reflect dysfunction in many organ systems. The clinical signs usually reflect the stimulatory nature of thyroid hormones on the various organ systems.
The diagnosis of feline hyperthyroidism is routinely made based on the measurement of elevated circulating levels of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). However thyroid hormone concentrations in cats with hyperthyroidism are subject to significant variation over time. Planar thyroid scintigraphy (or thyroid imaging) is useful in the detection of the hyperfunctional thyroid tissue that causes the disease. The major value of thyroid scintigraphy is determining the extent of the thyroid gland involvement. Thyroid scintigraphy is also invaluable in the evaluation of the thyroid carcinoma patient.
The therapy for hyperthyroidism is directed at controlling the excessive production of thyroid hormones. Four options for therapy are available; 1.) antithyroid drug administration, 2.) iodine deficient diets, 3.) surgery, and 4.) radioactive iodine. Of these therapies, the most recent is the newly developed Iodine deficient diet Hill’s y/d that has been shown to lower circulating thyroid hormone levels in hyperthyroid cats. When used to treat hyperthyroidism, strict adherence to these diets is required, as even small amounts of regular cat food will negate their effect. Because these diets require lifetime administration and should not be fed to cats with normal thyroid function, multi-cat households may experience difficulty with this form of therapy. Antithyroid drug administration will inhibit the synthesis of thyroid hormones. Methimazole (Tapazole®) is currently the antithyroid drug of choice. Antithyroid drug therapy is lifetime with symptoms of the disease recurring rapidly following discontinuation of the drug. Surgical thyroidectomy is a highly effective therapy for feline hyperthyroidism. Unfortunately anesthetic and surgical complications can result in significant morbidity and mortality. Greater than 70% of the cats with hyperthyroidism have bilateral thyroid involvement. In cats with bilateral thyroid involvement, removal of both lobes is necessary to control hyperthyroidism. Post-operative complications include hypoparathyroidism, Horner’s syndrome, laryngeal paralysis and persistent hypothyroidism.
Radioactive Iodine 131
Radioactive iodine (131I) therapy is currently the therapy of choice in most cases of feline hyperthyroidism. Radioactive iodine is preferentially concentrated in the adenomatous areas of the thyroid while the normal thyroid tissue takes up relatively little iodine due to normal feed back suppression. The ß (beta) particle emitted by 131I travels an average distance of 400 µm. This treatment is therefore locally destructive but spares the adjacent hypoplastic (normal) thyroid tissue as well as the parathyroid and other cervical tissues.
Radiation safety precautions require that cats remain hospitalized following their 131I therapy until they have eliminated a majority of the radioactive iodine from their bodies. This typically requires a hospitalization of 3 to 7 days. Radioactive iodine therapy is considered the optimum treatment for feline hyperthyroidism. It involves a single nonstressful procedure that is without associated morbidity or mortality. Significant side effects have not been observed. Unlike surgery, anesthesia is not necessary. A single dose of radioactive iodine will result in a return to persistent euthyroidism (normal thyroid function) in a majority (>95%) of cats with hyperthyroidism. Since the cat’s thyroid function returns to normal following 131I therapy, no ongoing thyroid medications are needed following this form of treatment.
Nuclear scintigraphy images of a normal cat and a cat with bilateral thyroid adenoma tumors.
FELINE RENAL FAILURE
Kidney failure is the inability of the kidneys to remove waste products from the blood. The buildup of toxic wastes produces the signs and symptoms of uremic poisoning. Kidney failure can come on acutely or occur gradually over weeks or months. Chronic renal failure is a leading cause of death in pet cats.
Causes of acute kidney failure include the following:
- A blockage in the lower urinary tract associated with feline lower urinary tract disease (FLUTD) or a congenital bladder defect
- Trauma to the abdomen, especially when accompanied by pelvic fracture and rupture of the bladder or urethra
- Shock, when due to sudden blood loss or rapid dehydration
- Arterial thromboembolism (a blood clot blocking the artery), particularly when both renal arteries are obstructed
- Heart failure, when associated with a persistently low blood pressure and reduced blood flow to the kidneys
- Poisoning, especially from ingesting antifreeze or Easter lilies
Causes of chronic kidney failure include these:
- Nephritis and nephrosis, in which case the failure is usually of the renal tubules, not the glomeruli.
- Infectious diseases, especially feline infectious peritonitis and feline leukemia.
- The use of nonsteroidal anti-inflammatory drugs (NSAIDs), especially during periods of hypotension (low blood pressure such as occurs during anesthesia).
- Various toxins. Antibiotics that are poisonous to the kidneys when given for prolonged periods or in high doses include polymyxin B, gentamicin, amphotericin B, and kanamycin. The heavy metals mercury, lead, and thallium are also toxic to the kidneys.
- Most elderly cats, if they live long enough, will have some degree of kidney insufficiency.
- Chronic renal failure and hyperthyroidism seem to often go hand in hand, since they are both geriatric diseases. Treatment of hyperthyroidism may unmask underlying chronic renal failure.
Cats with kidney diseases do not begin to show signs of uremia until about 70 percent of their nephrons are destroyed. Thus, a considerable amount of damage occurs before any signs are noted. The degree of renal failure can be determined by looking at laboratory data and tracking the progression of certain parameters.
One of the first signs of kidney failure is an increase in the frequency of voiding. Because the cat is voiding frequently, it might be assumed that her kidneys are functioning properly. Actually, the kidneys are no longer able to conserve water efficiently. Cats will go to the litter box several times a day and may also begin to urinate outside the box, since the box is getting dirty faster. This large urine output must be compensated for by increased fluid intake, and the cat will drink a lot more than usual. Also, because the urine is dilute (not concentrated), bacterial infections of the bladder and kidneys are much more common.
As renal function continues to deteriorate, the cat begins to retain ammonia, nitrogen, acids, and other waste products in the bloodstream and tissues (uremic poisoning). Blood chemistries will determine the exact levels of these metabolic products. Cats in the later stages of kidney failure may produce less urine than normal and, eventually, no urine at all, which leads to rapid decline.
Signs of uremia include apathy and sluggishness, loss of appetite and weight, dry haircoat, a brownish discoloration to the surface of the tongue, and ulcers on the gums and tongue. The breath may have an ammonialike odor. Vomiting, diarrhea, anemia, and episodes of gastrointestinal bleeding can occur. Eventually, the cat falls into a coma and dies.
Common Signs of Renal Disease
|Increased thirst||Nausea and gagging||Lethargy|
|Licking lips||Grinding or cracking sound in jaw||Depression|
|Vomiting (both clear/foamy liquid and food)||Drooling||Detached retina|
|Dehydration||Hunching over the water bowl||Weakness|
|Stomach irritation (uremic gastritis)||Constipation||Oral ulcers|
|Loss of appetite||Weight loss||Eating litter|
|Muscle wasting||Emaciation||Poor hair coat|
|Halitosis (ammonia smell)|
Diagnosing kidney failure may require a number of techniques. X-rays, with or without dye studies, along with ultrasound evaluations, can be important. Blood work, especially blood chemistry panels that look for toxic waste levels in the blood, should be done. Many cats will show increased levels of BUN (blood urea nitrogen), creatinine, and phosphorus. Anemia will show up in cats with chronic renal failure.
A urinalysis will show if the kidneys can still filter and concentrate the urine. Looking at urine sediment may suggest a cause for the kidney failure. ERD-HealthScreen is an early detection test that looks for the protein albumin in the urine (microalbuminuria). It is hoped that with early detection and treatment, the progression of kidney failure can be slowed. However, many inflammatory conditions, such as gingivitis, may also cause microalbuminuria.
Acute kidney failure can be reversed if the underlying cause can be corrected before it permanently damages the nephrons. If the insult is severe, hemodialysis (more commonly called dialysis) may be necessary to try to give the kidneys a chance to heal. Dialysis is most commonly used short term to treat acute renal failure or toxicities, or while a search is conducted for a transplant candidate. Dialysis is extremely expensive, can only be done at a few veterinary referral centers, and still requires extensive medical management of the cat in addition to the dialysis sessions.
Most cases of chronic kidney failure occur in cats who have sustained irreversible damage to the kidneys. However, these cats may still have many happy months or years of life ahead, with proper treatment. It is extremely important to be sure these cats take in enough water to compensate for their large urine output. A supply of fresh, clean water should be available at all times. Many cats will need supplemental fluids, given either intravenously at the veterinary hospital or subcutaneously at home.
The diet of a uremic cat should include protein of high quality, but lower in total amount, to minimize the amount of phosphorus and nitrogen that must be excreted by the kidneys. Special diets are available through your veterinarian. Canned foods are better than dry foods, because the canned food adds fluid to the diet. Prescription diets that are used for cats with kidney failure include Royal Canin Renal MP and Royal Canin Renal LP 21. Dr. Innes can also guide you to appropriate homemade diets.
Phosphorous restriction in the diet is important, although phosphate binders, such as aluminum hydroxide salt (Amphogel) can also be given. Vetoquinol has produced a veterinary product called Epakitin that is a palatable powder that also binds phosphates. However, this product also contains calcium, which may be contraindicated in the later stages of renal failure.
Large amounts of B vitamins are lost in the urine of uremic cats. These losses should be replaced by giving vitamin B supplements or in the subcutaneous fluids. Sodium bicarbonate tablets may be indicated to correct an acid-base imbalance. Potassium may also need to be supplemented. The kidneys are also important in the production of vitamin D. Cats in chronic renal failure may benefit from the addition of calcitriol to their therapeutic regimen. Dr. innes may need to order special compounded versions of calcitriol to get the appropriate dosage for a cat.
Vomiting may need to be controlled with medications such as famotidine, ranitidine, omeprazole, or others, until the renal condition is stabilized.
Erythropoietin (a bone marrow stimulating hormone) may be used to help counteract the anemia associated with long-term renal failure. Currently, human recombinant erythropoietin is used, which may lead to immune-based destruction of red blood cells and a renewal of the anemia over time. Research is continuing for a safe feline alternative.
Cats with hypertension will need therapy to lower their blood pressure.
A uremic cat who becomes ill, dehydrated, or fails to drink enough water may suddenly decompensate; this is known as a uremic crisis. The cat should be hospitalized and rehydrated with appropriate intravenous fluids and balanced electrolyte solutions.
Another option to consider for cats with terminal kidney failure is a kidney transplant. Kidney transplants are only done at a few veterinary referral centers but are becoming more common. As with human transplant patients, drugs must be given post-transplant to prevent rejection problems. These drugs are quite expensive and must be carefully calibrated to minimize side effects. Also, it was recently reported that cats are at a higher risk for developing diabetes due to the use of these drugs.
The current method for finding kidney donors is to test shelter cats for tissue compatibility. The shelter cat then donates one kidney-cats, like people, can do fine with just one healthy kidney. The shelter cat is then adopted by the family of the recipient cat, who must agree ahead of time to provide a home for the donor cat for the rest of her life.
ULTRASONOGRAPHIC IMAGES OF THE FELINE KIDNEY
FELINE LEUKEMIA VIRUS
What is feline leukemia virus?
Feline leukemia virus (FeLV), a retrovirus, so named because of the way it behaves within infected cells. All retroviruses, including feline immunodeficiency virus (FIV) and human immunodeficiency virus (HIV), produce an enzyme, reverse transcriptase, which permits them to insert copies of their own genetic material into that of the cells they have infected. Although related, FeLV and FIV differ in many ways, including their shape: FeLV is more circular while FIV is elongated. The two viruses are also quite different genetically, and their protein consituents are dissimlar in size and composition. Although many of the diseases caused by FeLV and FIV are similar, the specific ways in which they are caused differs.
How common is the infection?
FeLV-infected cats are found worldwide, but the prevalence of infection varies greatly depending on their age, health, environment, and lifestyle. In the United States, approximately 2 to 3% of all cats are infected with FeLV. Rates rise significantly—13% or more—in cats that are ill, very young, or otherwise at high risk of infection.
How is FeLV spread?
Cats persistently infected with FeLV serve as sources of infection. Virus is shed in very high quantities in saliva and nasal secretions, but also in urine, feces, and milk from infected cats. Cat-to-cat transfer of virus may occur from a bite wound, during mutual grooming, and (though rarely) through the shared use of litter boxes and feeding dishes. Transmission can also take place from an infected mother cat to her kittens, either before they are born or while they are nursing. FeLV doesn’t survive long outside a cat’s body—probably less than a few hours under normal household conditions.
What cats are at greatest risk of infection?
Cats at greatest risk of infection are those that may be exposed to infected cats, either via prolonged close contact or through bite wounds. Such cats include:
- Cats living with infected cats or with cats of unknown infection status
- Cats allowed outdoors unsupervised, where they may be bitten by an infected cat
- Kittens born to infected mothers
Kittens are much more susceptible to infection than are adult cats, and therefore are at the greatest risk of infection if exposed. But accompanying their progression to maturity is an increasing resistance to FeLV infection. For example, the degree of virus exposure sufficient to infect 100% of young kittens will infect only 30% or fewer adults. Nonetheless, even healthy adult cats can become infected if sufficiently exposed.
What does FeLV do to a cat?
Feline leukemia virus adversely affects the cat’s body in many ways. It is the most common cause of cancer in cats, it may cause various blood disorders, and it may lead to a state of immune deficiency that hinders the cat’s ability to protect itself against other infections. The same bacteria, viruses, protozoa, and fungi that may be found in the everyday environment—where they usually do not affect healthy animals—can cause severe illness in those with weakened immune systems. These secondary infections are responsible for many of the diseases associated with FeLV.
What are the signs of disease caused by FeLV?
During the early stages of infection, it is common for cats to exhibit no signs of disease at all. However, over time—weeks, months, or even years—the cat’s health may progressively deteriorate or be characterized by recurrent illness interspersed with periods of relative health. Signs can include:
- Loss of appetite
- Slow but progressive weight loss, followed by severe wasting late in the disease process
- Poor coat condition
- Enlarged lymph nodes
- Persistent fever
- Pale gums and other mucus membranes
- Inflammation of the gums (gingivitis) and mouth (stomatitis)
- Infections of the skin, urinary bladder, and upper respiratory tract
- Persistent diarrhea
- Seizures, behavior changes, and other neurological disorders
- A variety of eye conditions
- In unspayed female cats, abortion of kittens or other reproductive failures
I understand there are two stages of FeLV infection. What are they?
FeLV is present in the blood (a condition called viremia) during two different stages of infection:
- Primary viremia, an early stage of virus infection. During this stage some cats are able to mount an effective immune response, eliminate the virus from the bloodstream, and halt progression to the secondary viremia stage.
- Secondary viremia, a later stage characterized by persistent infection of the bone marrow and other tissue. If FeLV infection progresses to this stage it has passed a point of no return: the overwhelming majority of cats with secondary viremia will be infected for the remainder of their lives.
How is infection diagnosed?
Two types of FeLV blood tests are in common use. Both detect a protein component of the virus as it circulates in the bloodstream.
- ELISA (enzyme-linked immunosorbent assay) and similar tests can be performed in your veterinarian’s office. ELISA-type tests detect both primary and secondary stages of viremia.
- IFA (indirect immunofluorescent antibody assay) tests must be sent out to a diagnostic laboratory. IFA tests detect secondary viremia only, so the majority of positive-testing cats remain infected for life.
Each testing method has strengths and weaknesses. Your veterinarian will likely suggest an ELISA-type test first, but in some cases, both tests must be performed—and perhaps repeated—to clarify a cat’s true infection status.
How can I keep my cat from becoming infected?
The only sure way to protect cats is to prevent their exposure to FeLV-infected cats.
- Keep cats indoors, away from potentially infected cats that might bite them. If you do allow your cat’s outdoor access, provide supervision or place them in a secure enclosure to prevent wandering and fighting.
- Adopt only infection-free cats into households with uninfected cats.
- House infection-free cats separately from infected cats, and don’t allow infected cats to share food and water bowls or litter boxes with uninfected cats.
- Consider FeLV vaccination of uninfected cats. (FeLV vaccination of infected cats is not beneficial.) Discuss the advantages and disadvantages of vaccination with your veterinarian. FeLV vaccines are widely available, but since not all vaccinated cats will be protected, preventing exposure remains important even for vaccinated pets. FeLV vaccines will not cause cats to receive false positive results on ELISA, IFA, or any other available FeLV tests.
I just discovered that one of my cats has FeLV, yet I have other cats as well. What should I do?
Unfortunately, many FeLV-infected cats are not diagnosed until after they have lived with other cats. In such cases, all other cats in the household should be tested for FeLV. Ideally, infected and non-infected cats should then be separated to eliminate the potential for FeLV transmission.
How should FeLV-infected cats be managed?
- Confine FeLV-infected cats indoors to reduce their exposure to other infectious agents carried by animals, and to prevent the spread of infection to other cats in the neighborhood.
- Spay or neuter FeLV-infected cats.
- Feed nutritionally complete and balanced diets.
- Avoid uncooked food, such as raw meat and eggs, and unpasteurized dairy products because the risk of food-borne bacterial and parasitic infections is much higher in immunosuppressed cats.
- Schedule wellness visits with your veterinarian at least once every six months. Although a detailed physical examination of all body systems should be performed, your veterinarian should pay special attention to the health of the gums, eyes, skin, and lymph nodes. A complete blood count, serum biochemical analysis, and a urine analysis should be performed at every examination. Additionally, your cat’s weight should be accurately measured and recorded, as weight loss is often the first sign of deterioration.
- Closely monitor the health and behavior of your FeLV-infected cat. Alert your veterinarian to any changes in your cat’s health immediately.
- There is no scientific evidence that alternative, immunomodulator, or antiviral medications have any positive benefits on the health or longevity of healthy infected cats.
How long can I expect my FeLV-infected cat to live?
It is impossible to accurately predict the life expectancy of a cat infected with FeLV. With appropriate care and under ideal conditions, infected cats can remain in apparent good health for many months, although most succumb to a FeLV-related disease within two or three years after becoming infected. If your cat has already experienced one or more severe illnesses as a result of FeLV infection, or if persistent fever, weight loss, or cancer is present, a much shorter survival time can be expected.
My FeLV-infected cat died recently after a long illness. How should I clean my home before bringing in a new cat?
Feline leukemia virus will not survive outside the cat for more than a few hours in most environments. However, FeLV-infected cats are frequently infected with other hardier infectious agents, and these may pose some threat to a newcomer. Thoroughly clean and disinfect or replace food and water dishes, bedding, litter pans and toys. A dilute solution of household bleach (4 ounces of bleach in a gallon of water) makes an excellent disinfectant. Vacuum carpets and mop floors. Any new cats or kittens should be properly vaccinated before entering the household.
Can people become infected with FeLV?
Epidemiological and laboratory studies have failed to provide evidence that FeLV can be transmitted from infected cats to humans. Regardless, FeLV-infected cats may carry other diseases. At greatest risk of infection are elderly or immunosuppressed people (e.g., those with AIDS, or receiving immunosuppressive medications such as chemotherapy), infants, and unborn children. It is recommended that pregnant women, people with suppressed immune systems, the very young, and the very old avoid contact with FeLV-infected cats.
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FELINE IMMUNODEFICIENCY VIRUS
What is Feline Immunodeficiency Virus?
Virologists classify feline immunodeficiency virus (FIV) as a lentivirus (or “slow virus”). FIV is in the same retrovirus family as feline leukemia virus (FeLV), but the viruses differ in many ways including their shape. FIV is elongated, while FeLV is more circular. The two viruses are also quite different genetically, and the proteins that compose them are dissimilar in size and composition. The specific ways in which they cause disease differ, as well.
How common is the infection?
FIV-infected cats are found worldwide, but the prevalence of infection varies greatly. In the United States, approximately 1.5 to 3 percent of healthy cats are infected with FIV. Rates rise significantly-15 percent or more-in cats that are sick or at high risk of infection. Because biting is the most efficient means of viral transmission, free-roaming, aggressive male cats are the most frequently infected, while cats housed exclusively indoors are much less likely to be infected.
How is FIV spread?
The primary mode of transmission is through bite wounds. Casual, non-aggressive contact does not appear to be an efficient route of spreading FIV; as a result, cats in households with stable social structures where housemates do not fight are at little risk for acquiring FIV infections. On rare occasions infection is transmitted from an infected mother cat to her kittens, usually during passage through the birth canal or when the newborn kittens ingest infected milk. Sexual contact is not a major means of spreading FIV.
What does FIV do to a cat?
Infected cats may appear normal for years. However, infection eventually leads to a state of immune deficiency that hinders the cat’s ability to protect itself against other infections. The same bacteria, viruses, protozoa, and fungi that may be found in the everyday environment–where they usually do not affect healthy animals–can cause severe illness in those with weakened immune systems. These secondary infections are responsible for many of the diseases associated with FIV.
What are the signs of disease caused by FIV?
Early in the course of infection, the virus is carried to nearby lymph nodes, where it reproduces in white blood cells known as T-lymphocytes. The virus then spreads to other lymph nodes throughout the body, resulting in a generalized but usually temporary enlargement of the lymph nodes, often accompanied by fever. This stage of infection may pass unnoticed unless the lymph nodes are greatly enlarged.
An infected cat’s health may deteriorate progressively or be characterized by recurrent illness interspersed with periods of relative health. Sometimes not appearing for years after infection, signs of immunodeficiency can appear anywhere throughout the body.
- Poor coat condition and persistent fever with a loss of appetite are commonly seen.
- Inflammation of the gums (gingivitis) and mouth (stomatitis) and chronic or recurrent infections of the skin, urinary bladder, and upper respiratory tract are often present.
- Persistent diarrhea can also be a problem, as can a variety of eye conditions.
- Slow but progressive weight loss is common, followed by severe wasting late in the disease process.
- Various kinds of cancer and blood diseases are much more common in cats infected with FIV, too.
- In unspayed female cats, abortion of kittens or other reproductive failures have been noted.
- Some infected cats experience seizures, behavior changes, and other neurological disorders.
How is infection diagnosed?
Antibody tests detect the presence of antibody in the blood of infected cats.
- Because few, if any, cats ever eliminate infection, the presence of antibody indicates that a cat is infected with FIV. This test can be performed by most veterinary diagnostic laboratories and also is available in kit form for use in veterinary clinics. Since false-positive results may occur, veterinarians recommend that positive results be confirmed using a test with a different format.
- Infected mother cats transfer FIV antibodies to nursing kittens, so kittens born to infected mothers may receive positive test results for several months after birth. However, few of these kittens actually are or will become infected. To clarify their infection status, kittens younger than six months of age receiving positive results should be retested at 60-day intervals until they are at least six months old.
- A negative test result indicates that antibodies directed against FIV have not been detected, and, in most cases, this implies that the cat is not infected. Nevertheless, it takes eight to 12 weeks after infection (and sometimes even longer) before detectable levels of antibody appear, so if the test is performed during this interval, inaccurate results might be obtained. Therefore, antibody-negative cats with either an unknown or a known exposure to FIV-infected cats-such as through the bite of an unknown cat-should be retested a minimum of 60 days after their most recent exposure in order to allow adequate time for development of antibodies.
- On very rare occasions, cats in the later stages of FIV infection may test negative because their immune systems are so compromised that they no longer produce detectable levels of antibody.
Polymerase chain reaction (PCR) tests are designed to detect short segments of a virus’s genetic material. While antibody-based tests are ideal screening tests for infection, in certain situations (such as confirming infection in antibody-positive kittens or determining infection of cats vaccinated with antibody-producing FIV vaccines), PCR-based tests, in theory, would be superior. Although PCR testing methods offer promise and are being actively explored, at this time unacceptable numbers of false-positive and false-negative results prevent them from routinely being recommended.
How can I keep my cat from becoming infected?
The only sure way to protect cats is to prevent their exposure to the virus. Cat bites are the major way infection is transmitted, so keeping cats indoors-and away from potentially infected cats that might bite them-markedly reduces their likelihood of contracting FIV infection. For the safety of the resident cats, only infection-free cats should be adopted into a household with uninfected cats.
Vaccines to help protect against FIV infection are now available. However, not all vaccinated cats will be protected by the vaccine, so preventing exposure will remain important, even for vaccinated pets. In addition, vaccination may have an impact on future FIV test results. It is important that you discuss the advantages and disadvantages of vaccination with your veterinarian to help you decide whether FIV vaccines should be administered to your cat.
I just discovered that one of my cats has FIV, yet I have other cats as well. What do I do now?
Unfortunately, many FIV-infected cats are not diagnosed until after they have lived for years with other cats. In such cases, all the other cats in the household should be tested, as well. Ideally, all infected cats should be separated from the noninfected ones to eliminate the potential for FIV transmission. If this is not possible-and if fighting or rough play is not taking place-the risk to the non-infected cats appears to be low.
How should FIV-infected cats be managed?
- FIV-infected cats should be confined indoors to prevent spread of FIV infection to other cats in the neighborhood and to reduce their exposure to infectious agents carried by other animals.
- FIV-infected cats should be spayed or neutered.
- They should be fed nutritionally complete and balanced diets.
- Uncooked food, such as raw meat and eggs, and unpasteurized dairy products should not be fed to FIV-infected cats because the risk of food-borne bacterial and parasitic infections is much higher in immunosuppressed cats.
- Wellness visits for FIV-infected cats should be scheduled with your veterinarian at least every six months. Although a detailed physical examination of all body systems will be performed, your veterinarian will pay special attention to the health of the gums, eyes, skin, and lymph nodes. Your cat’s weight will be measured accurately and recorded, because weight loss is often the first sign of deterioration. A complete blood count, serum biochemical analysis, and a urine analysis should be performed annually.
- Vigilance and close monitoring of the health and behavior of FIV-infected cats is even more important than it is for uninfected cats. Alert your veterinarian to any changes in your cat’s health as soon as possible.
- There is no evidence from controlled scientific studies to show that immunomodulator, alternative, or antiviral medications have any positive benefits on the health or longevity of healthy FIV-infected cats. However, some antiviral therapies have been shown to benefit some FIV-infected cats with seizures or stomatitis.
How long can I expect my FIV-infected cat to live?
It is impossible to accurately predict the life expectancy of a cat infected with FIV. With appropriate care and under ideal conditions, many infected cats will remain in apparent good health for many months or years. If your cat has already had one or more severe illnesses as a result of FIV infection, or if persistent fever and weight loss are present, a much shorter survival time can be expected.
My FIV-infected cat died recently after a long illness. How should I clean my home before bringing in a new cat?
Feline immunodeficiency virus will not survive outside the cat for more than a few hours in most environments. However, FIV-infected cats are frequently infected with other infectious agents that may pose some threat to a newcomer. Thoroughly clean and disinfect or replace food and water dishes, bedding, litter pans, and toys. A dilute solution of household bleach (four ounces of bleach in 1 gallon of water) makes an excellent disinfectant. Vacuum carpets and mop floors with an appropriate cleanser. Any new cats or kittens should be properly vaccinated against other infectious agents before entering the household.
Can I become infected with FIV?
Although FIV is a lentivirus similar to HIV (the human immunodeficiency virus) and causes a disease in cats similar to AIDS (acquired immune deficiency syndrome) in humans, it is a highly species-specific virus that infects only felines.
A number of studies have failed to show any evidence that FIV can infect or cause disease in people.
Why should I have my cat tested?
Early detection will help you maintain the health of your own cat and also allow you to prevent spreading infection to other cats.
Under what circumstances should FIV testing be performed?
- If your cat has never been tested.
- If your cat is sick, even if it tested free of infection in the past but subsequent exposure can’t be ruled out.
- When cats are newly adopted, whether or not they will be entering a household with other cats.
- If your cat has recently been exposed to an infected cat.
- If your cat is exposed to cats that may be infected (for example, if your cat goes outdoors unsupervised or lives with other cats that might be infected). Your veterinarian may suggest testing periodically (yearly) as long as your cat is exposed to potentially infected cats.
- If you’re considering vaccinating with an FIV vaccine.
The technical term for feline diabetes is diabetes mellitus, also known as “sugar” diabetes for its reference to excess glucose in the bloodstream. It is a complex, but common, disease similar to diabetes in humans, in which the cat doesn’t produce sufficient insulin or doesn’t process the insulin produced by its own body. Insulin is a hormone secreted by the pancreas in small amounts and helps to properly balance the blood sugar (glucose) levels in the blood. Glucose is the fuel that provides energy needed by the cells of the body to sustain life.
The types of diabetes in cats are based on the human classification system.
Type 1 form of diabetes is defined as an absolute insulin deficiency. In this form, the pancreas is not able to produce enough insulin to regulate the glucose in the bloodstream, leading to persistent high glucose levels in the blood. This type of diabetes is very rare in the cat.
Type 2 Diabetes
Type 2 diabetes, the most common form of diabetes in cats, occurs when the cells in the cat’s body don’t respond to the insulin that is being provided. As a result, the cat becomes hyperglycemic (high blood sugar), which may lead to having excess sugar in the urine.
No test can differentiate between Type 1 or Type 2 diabetes in the cat.
Type 3 Diabetes
Type 3 diabetes is also less common and may occur due to other conditions (e.g., secondary to another primary disease which may damage the pancreas).
As in humans, diabetes is often seen in overweight cats because fat cells produce a substance that decreases the body’s response to insulin (as occurs in Type 2 diabetes).
In addition, diet plays a major role in maintaining the cat’s proper weight and nutrition, both of which are key determining factors in diabetic patients. Because cats are designed to consume mostly proteins and fats for energy in their diets, high carbohydrate diets may lead to weight gain and increased incidence of diabetes in many cats.
Further, diabetes is more prevalent in older cats, neutered male cats and felines with a history of pancreatic disease, hormonal imbalances and use of certain medications.
Dr. Innes can diagnose diabetes with a simple, in-office physical examination of the cat and laboratory tests, which will determine if there is an abnormally high level of sugar in the bloodstream and urine.
Dr Innes will ask if your cat has exhibited any of the following symptoms, indicating a possibility of feline diabetes:
- Increased thirst
- Sudden increase in appetite
- Sudden weight loss (despite an increase in appetite)
- Increased urination
- Increased lethargy
Common types of insulin used in feline diabetes.
Understanding Your Cat’s Diagnosis
The food your cat eats is broken down into glucose during the digestion process. Glucose is the fuel that provides energy needed by the cells of the body to sustain life. As glucose enters the bloodstream, the cat’s pancreas secretes insulin. Insulin is a hormone released in small amounts to properly balance the blood sugar (glucose) levels in the blood.
Feline diabetes is similar to human diabetes, and occurs when your pet either doesn’t produce or is unable to process insulin, a hormone that helps regulate glucose or sugar in the bloodstream.
Just like humans, diabetic cats are diagnosed primarily with Type 2 diabetes.
My cat has just been diagnosed with diabetes … now what?
Discovering that your pet has diabetes can seem overwhelming and scary especially since there is no cure. The good news is that feline diabetes is not a fatal diagnosis and with proper attention, your cat can live a happy and virtually normal life and in some well managed cats the diabetic state may be transient and revert back to normal.
Learning how to monitor your cat’s blood sugar levels will be one of the most important aspects of caring for your diabetic cat. Dr. Innes may run these tests in the hospital or may demonstrate how to test your cat’s blood sugar levels at home, either through urine or blood sample testing.
Additionally, feeding your cat on a regular schedule will help prevent dips and spikes in the cat’s glucose levels. Again, Dr. Innes will discuss specific dietary changes and options to best fit your cat, your family and your lifestyle.
Finally, it’s important to understand that you and your cat are not alone — the more you know about this disease, the easier it can be to manage.
Hypoglycemia vs. hyperglycemia
Hypoglycemia is the medical term for low blood sugar. Diabetics have the opposite problem of hyperglycemia, or high blood sugar.
Diabetic cats can develop hypoglycemia (low blood sugar) when their diet and treatment is managed incorrectly. Symptoms of hypoglycemia include:
- Abnormal hunger or disinterest in food
- Weakness or lethargy
- Staggering or uncoordinated movements
- Loss of eyesight
If your cat experiences symptoms of hypoglycemia it is recommended to contact your veterinarian for advice. In the meantime, you can try feeding the cat some of its normal food. If the cat is unwilling to eat, try encouraging the cat by offering a small amount of corn syrup on the food. In cases of extreme condition, contact your veterinarian and take your cat in immediately.
Hyperglycemia is when your cat’s blood sugar levels are too high, resulting in the primary symptoms of feline diabetes, including:
- Increased thirst
- Sudden increase in appetite
- Sudden weight loss (despite an increase in appetite)
- Increased urination
- Increased lethargy
Generally, hyperglycemia is not life-threatening and can be controlled through administering insulin. Dr. Innes will work with you to develop a regimen for testing and controlling your cat’s blood sugar levels to avoid hypo- and hyperglycemia.
Living with a Diabetic Cat
Each diabetic cat responds differently to different therapies. Some cats are easier to regulate; others require more complex types of treatment. Some cats can be treated successfully through changes in diet and with oral medications. In cats with more severe diabetes, insulin injections may be required for the remainder of their lives.
In general, treatment for diabetes falls into three categories:
- Insulin injections
- Oral hypoglycemic medications
Home Monitoring & Testing
Ongoing and frequent home monitoring of your cat’s glucose level is important both for ensuring that diabetes is under control and the long-term health maintenance of your pet. Home monitoring usually results in less stress on the cat and allows for closer, more precise control of blood glucose levels on a regular basis, which helps avoid the risk of hypoglycemic episodes.
Home testing of glucose levels can be done with a similar type of blood glucose monitor used by humans. This method requires a small sample of blood that is taken from the cat for testing and generally provides an immediate reading of your cat’s blood glucose level.
In addition to monitoring glucose levels through the blood, caretakers can use urine glucose monitoring. However, urine glucose monitoring is generally not as accurate due to the lag time for glucose to go from the blood to the urine in the cat’s body.
It is recommended to consult with Dr. Innes on the best way to monitor your cat’s glucose. They can also provide valuable advice on which type(s) of monitors work best in cats, as well as train you on how to use and interpret the test results.
When at home, you also should continually be aware of your cat’s appetite, water consumption and urine output to determine what is normal behavior. Changes in your cat’s eating and drinking habits, weight and urine output can be a sign that there is a problem and veterinary attention is needed.
Along with insulin and rarely oral medications, maintaining a proper diet for your cat is important in a successful treatment program. Obesity is a major risk factor for diabetes and insulin sensitivity in most cats. If your cat is overweight, you and your veterinarian can tailor a safe weight loss regimen. Some cats respond better to carbohydrate-restricted diets and some respond well to high-fiber, complex carbohydrate rations.
In addition to the type of diet fed, the feeding routine also is important, especially for cats receiving insulin injections. Ideally, a cat should be fed half its daily food requirement at the time of each injection, with the rest available throughout the day. When and how much to feed your cat should be discussed with Dr. Innes as other factors may impact this process, (e.g., number of insulin injections/day or living in a multi-cat household).
Most diabetic cats require insulin injections under the skin once or twice a day, depending on the diabetic severity, type of insulin used, dose, diet and other factors. Because each cat reacts differently to insulin, Dr. Innes will most likely perform a blood glucose profile at various time points during the day to determine the proper insulin dosage and treatment program. Insulin dosage may change over time as the cat ages, and you may need to adjust the dosage based on new blood glucose profiles, test results and how the cat responds to therapy. It is very important to consult with a veterinarian before making any changes to your cat’s insulin dose. Many factors are involved with a decision to increase or decrease dose and you want to avoid causing hypoglycemia in your cat.
There are several different types of insulin available for use in managing your cat’s diabetes. Some of the most common include protamine zinc (PZI) insulin, lente insulin, Humulin® and other human-type products.
Diabetes Key Words
Oral Hypoglycemic Medications
Some healthy diabetic cats can be successfully treated with orally administered hypoglycemic medications that lower blood glucose levels. Often, the use of these medications requires frequent glucose monitoring to ensure the best results, and many cats still require insulin injections to achieve the highest level of control.
Ketones are waste products of fatty acids that may build up in the bloodstream and urine of cats with diabetes. Ketones develop when the cat’s body burns fat, instead of glucose, to fuel its body. If your cat accumulates too many ketones in the body, diabetic ketoacidosis (DKA) may occur. This is a serious condition altering the pH and blood chemistry of your pet, and should be treated immediately.
Signs your cat may have diabetic ketoacidosis:
- Drinking excessive water or no water
- Excessive urination
- Diminished activity
- Not eating for 12 hours or more
- Lethargy or depression
- Ketone odor on the breath (may smell like nail-polish remover or fruit)
Simple urine tests will alert you to the presence of ketones. If you discover ketones in your cat’s urine sample, check to see if your cat is exhibiting any of the symptoms of diabetic ketoacidosis listed above. If the cat is generally alert and well-hydrated, simply treat the cat with your normal insulin regimen, provide the cat with continual access to food and water, and monitor the cat for signs of diabetic ketoacidosis. If the cat develops signs of DKA, contact your veterinarian immediately.
Or sugar diabetes, is a commonly diagnosed disease in cats and ultimately affects all the organs. It develops in about 1 in 400 cats. It is due to inadequate production of insulin by the beta cells in the pancreas or inadequate response of the cells to insulin. Insulin is secreted directly into the circulation. It acts upon cell membranes, enabling glucose to enter the cells, where it is metabolized for energy. Without insulin, the body can’t utilize glucose. This results in elevated blood sugar levels (hyperglycemia). In diabetic cats, excess glucose is eliminated by the kidneys, producing frequent urination. There is a need to compensate for the increased urination by drinking unusual amounts of water.
Such as megestrol acetate (Megace), and some corticosteroids, all have the potential to cause or mimic diabetes in a cat. Obesity is a predisposing factor for all cats, and Burmese cats may have a genetic predisposition. Male cats have twice the risk of females. At greatest risk are neutered male cats over 10 years of age and over 15 pounds in weight.
Glucosuria is sugar in the urine. When a urine glucose test is positive, suspect diabetes. Some cats will show high glucose levels in urine and blood due to stress, however, so a repeat test may be needed to verify the results. Defects in the kidney tubule function, such as with antifreeze poisoning, may also cause high glucose levels in the blood and urine.
Ketones (the end-product of rapid or excessive fatty-acid breakdown) are formed in the blood of diabetics because of the inability to metabolize glucose. High levels lead to a condition called ketoacidosis. It is characterized by acetone on the breath (a sweet odor like nail polish remover); rapid, labored breathing; and, eventually, diabetic coma.
Everyone can understand the importance of dental care for their pets, because the risk of gingivitis and periodontal disease is the same for animals as it is for people.
Dental disease is one of the most common medical problems seen in routine feline practice. There is no reason to believe that animals do not feel the same pain of sore gums and a toothache that we feel. So, the main reason to care for your pet’s teeth is to prevent pain.
If you never brushed your teeth, your mouth would be sore and you would have trouble eating. You might feel tired all the time because the infection in your mouth would spread throughout your body. The exact same thing happens in your pet’s mouth. The mouth is the door to the rest of the body. It has a very good immune system to protect it against the constant barrage of bacteria and toxins it deals with every minute. But it needs some help. We must keep it clean of the plaque that is constantly forming on the teeth.
Plaque is a clear, thick substance consisting of saliva, bacteria, and food particles. In fact, plaque is 80% bacteria and forms within 6-8 hours after brushing. It sticks to the teeth and collects in the pockets around the teeth. If not removed, an infection will result. This infection will eventually overwhelm the body’s immune system. This dental plaque also leads to bad breath, gum disease, and eventually leads to tartar/calculus accumulation, and eventual periodontal disease and loss of teeth. More importantly, tartar and plaque are also linked to more serious problems, such as liver, kidney, joint disease, and heart disease. Routine dental care may save more than your pet’s smile, therefore, dental exams and cleaning are recommended annually.
Multiple examples of feline gingivitis and periodontal disease!
Pet dentistry has become an established aspect of good veterinary care. And for good reason!
Method and Equipment
We use an advanced human piezo-electric dental scaler (most vets use a simpler ultrasonic scaler) that allows us to clean teeth thoroughly and efficiently. The various tips allow for removal of large amounts of tartar as well as more delicate cleaning below the gum margin. We also use hand scalers when needed and then polish the teeth just like when you have your teeth cleaned. Lastly, a sealant can be applied to the teeth to help prevent further plaque build-up.
Our dental table includes both high- and low-speed drills when needed for extractions and all of our surgical equipment is steam sterilized for each patient.
Anesthesia is an area of concern for most pet owners. We examine your pet and his or her medical history to develop a protocol specifically for them. This often includes routine blood work to ensure there are no underlying liver, kidney, infections, anemia, or other physiological problems that could put your pet at risk for anesthesia.
We use state-of-the-art monitoring equipment that includes ECG, Oxygen saturation of the blood, carbon dioxide levels, blood pressure and temperature.
Dr. Innes has two decades of experience monitoring patients under anesthesia.
There are various pre-anesthetic medications that are utilized, depending on the dog’s size and Dr. Innes’ preference. After the animal is relaxed general anesthesia is induced. This, too, can be in various forms. One under general, an endotracheal tube is placed to provide a “safe” airway so anesthesia can be maintained with 100% oxygen and human grade anesthetic gas.
Inside the mouth, we utilize lidocaine gel along the gum margin and local anesthetic blocks to reduce pain and allow us to keep our general anesthesia level as low as possible. Your pet’s safety and comfort are of paramount importance to us.
Gingivitis and Periodontal Disease
Periodontal disease is a disease of the tissues that support the teeth in the mouth. Both bacterial infection and inflammation play a role in this pervasive disease of dogs, cats and people. These tissues are the gums, the jaw bone, and the periodontal ligament which connects the tooth to the bone. Periodontal disease occurs when the body’s immune system reacts to the bacteria and toxins which are constantly forming on the teeth in the form of plaque.
If plaque is not removed, it will eventually accumulate and harden into dental calculus also called tartar. Calculus can become a hard yellow brownish covering over the crowns of the tooth. It’s like cement and is difficult to remove. With heavy build-up, calculus can also cover the gum so that the plaque beneath the gum-line cannot be cleaned. This build-up exacerbates the situation, creating a nice environment in which the nastiest plaque bacteria thrive. The plaque beneath the gum-line is the real enemy in periodontal disease. Fortunately plaque that is above the gumline is removeable with tooth brushing. As the plaque accumulates and the bacteria multiply, the pockets around each tooth become deeper and more painful for your pet. An early sign of this stage is a swelling and reddening at the gum-line around each tooth. If you touch this area, your pet may shy away and the gums may bleed. This is gingivitis, the earliest form of periodontal disease. Gingivitis is a reversible inflammation of the gums. If the teeth and gums are cleaned now, the mouth can be “as good as new.” However, if the pockets around the teeth are deep enough, the gums recede, or the bone supporting the teeth begin to resorb, irreversible changes have occurred in the mouth. This is advanced periodontal disease. At this stage the disease can be arrested, but the damage it has caused cannot be completely reversed.
The pictures above show what severe calculus and periodontal disease look like visually and with digital radiographs. Note there is severe bone loss around the tooth root
This cat has a deep pocket on the inside of the canine tooth (note depth of probe
There is a hole between the tooth and the nasal cavity called an oronasal fistula – see below
Just like humans, pets can break their teeth. A tooth fractures due to trauma, such as chewing on something that is too hard. The most common causes of fractured teeth that we see are: cow hooves, hard nylon toys, ice cubes, rocks, and marrow bones. A fractured tooth with pulp exposure allows bacteria to enter the tooth, leading to pain and infection. Often a stoic animal may not show outward signs of oral pain but will show dramatic signs of improvement once the tooth is treated surgically. It is not unusual for an owner to be unaware that their pet has a fractured tooth until the infection has become so bad that it causes facial swelling. Antibiotics will help to temporarily treat the infection, but once the medication is stopped, the infection will return. We always recommend treating a fractured tooth with pulp exposure either with root canal therapy or extraction. If you suspect that your cat or dog has a broken tooth please contact our office for an appointment with Dr. Innes.
This is an example of class 3 fracture of a canine tooth (into root canal).
Extractions are another area of concern for pet owners. We try and keep as many teeth in your pet’s mouth as possible, but leaving a diseased tooth behind would lead to continue discomfort and systemic effects for your pet.
When extractions are necessary, like the fractured teeth seen above or teeth with severe periodontal disease, we start with long acting (6-8 hours) local anesthetic blocks to “numb” the area where the tooth is to be extracted. In addition, opiod pain medications and antibiotics are administered. We then perform surgical extractions that result in less trauma and faster healing with the surgical opening closed with absorbable sutures.
Broken and Retained Deciduous Teeth
Broken and retained deciduous teeth should also be extracted. The teeth that are present around 6 weeks of age are not the permanent teeth the puppy will have as an adult. Like humans, dogs have two sets of teeth that develop during their lifetime. The first set of teeth, sometimes called “baby” teeth are also called deciduous teeth because these teeth are present early in life, and then are shed as the developing permanent teeth erupt into position. Deciduous teeth are typically lost or shed as the roots of these teeth are resorbed and the crown becomes loose. If the deciduous tooth is not shed in a timely manner, we refer to them as “retained”. Retained deciduous teeth should be removed, provided there is a permanent tooth to replace it.
Deciduous teeth in puppies are usually present at 5-6 weeks of age and are lost between 3-6 months. One of the best times to evaluate for retained deciduous teeth is at the time of the spay or neuter surgery. Since the pet will already be under anesthesia, this creates an excellent opportunity to remove any retained deciduous teeth that might cause further problems. The root of a deciduous tooth is amazingly large. What you see of a deciduous tooth above the gumline is only about 25% of the entire tooth.
As a general rule of thumb, there should only be one tooth occupying a specific place. More simply put, if there is a permanent tooth that has erupted through the gingiva and a deciduous tooth remains, the deciduous tooth should be removed to prevent possible deflection of the permanent tooth’s eruption path, or to prevent crowding of the two involved teeth, which could lead to periodontal problems that could affect the permanent tooth.
A discolored tooth can occur after trauma. Typically this happens when a pet chews on hard objects or from blunt trauma to the mouth. The pulp of the tooth bleeds and initially stains the dentin pink. Eventually the tooth will become a purple or grey.
A study reported in the Journal of Veterinary Dentistry by Dr. Fraser Hale (JVD, Vol18:1, March 2001 and the Veterinary Dental Forum in October 2001) showed that 94% of discolored teeth suffer from partial or total pulp necrosis and only 58% of those show radiographic signs of necrosis. The study concluded that discolored teeth need to be either extracted or treated with root canal therapy.
We recommend that discolored teeth (even partially discolored) are either extracted or treated with root canal therapy. If you suspect that your cat has a discolored tooth, please contact our office to schedule an appointment with Dr. Innes.
An oronasal fistula is a hole in the palatal oral soft tissue and bone that communicates with the nasal sinus. They can be caused by trauma, such as a maloccluded tooth or from periodontal disease. Cats with severe periodontal disease around their upper canine teeth as seen above are commonly affected by oronasal fistulas secondary to periodontal disease of their upper canine teeth. Pets will frequently sneeze or reverse sneeze because food and other debris becomes lodged in their nose. Also owners might notice a discharge from either one or both nostrils. An oronasal fistula will not heal on its own and does require surgical intervention. If your pet is sneezing or having nasal discharge and you suspect an oronasal fistula, please contact our office to schedule an appointment with Dr. Innes.
This is an oronasal fistula, an opening where an upper canine tooth once was. The opening communicates between the mouth the nose resulting in food and infection getting into the nasal cavity with resultant sneezing and nasal discharge. Surgery is needed to close the defect!
Feline Oral Cancer
The words “tumor” or “cancer” strike fear into pet owners and for good reason. Fortunately, the term tumor does not always mean a mass that will spread throughout the body. Tumor can mean a benign mass, that is one that does not spread to other parts of the body, or malignant, which means a mass that has the potential to spread to other areas. All tumors behave differently based on their type with some never spreading, some invading the tissues where they are, and some spreading out within the local tissues and spreading to other areas of the body.
Oral neoplasias (tumors) account for 10% of all tumors in cats. Of these, 90% are malignant in cats. Many oral masses look alike, whether benign or malignant. The key to successful treatment planning is early detection and microscopic evaluation (biopsy) of all oral masses. Small lesions may seem insignificant due to their size, but if the mass turns out to be malignant, obtaining adequate surgical margins without major structural loss is much easier with lesions less than 1 cm than those larger. In most cases, complete surgical removal of oral tumors early in the course of disease is the preferred treatment. Dental radiographs can be a valuable diagnostic tool when evaluating oral masses.
Generalities about oral tumors:
In general, benign tumors do not typically invade bone, as such, these lesions tend to deflect teeth and alter their position. On the other hand, malignant masses can be invasive into bone, and usually remove bone around tooth roots without displacing teeth. Notation of lymph node size and consistency along with chest x-rays, abdominal ultrasound, and other diagnostic modalities such as Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) can also be helpful especially when staging oral tumors. Most benign lesions can be removed with small surgical margins extending into clinically healthy tissue only. The exception to this rule is the acanthomatous epulis (aka acanthomatous ameloblastoma, central odontogenic fibroma, adamantanoma). These tumors are technically benign because they have never been shown to spread to other organs, but they can invade into the bone surrounding teeth. The acanthomatous epulis is also very sensitive to radiation therapy. Treatment with either radiation therapy or surgical removal with clean margins carries an excellent prognosis (95+%).
Malignant tumors require 1-2cm surgical margins into clinically and radiographically healthy tissue. The most common oral malignancies in cats are squamous cell carcinoma is the most common oral malignancy in the cat. If caught early, many of these oral tumors can successfully be removed surgically. Those with higher potential to spread should have continued monitoring for early detection of other tumors. Regional lymph node aspirate prior to surgery or lymph node excision is advocated. Consultation with an oncologist with any malignancy is also recommended to consider all treatment options.
TYPICAL PRESENTATION OF ORAL MASSES
Typical presentation of oral masses. If your cat has an oral growth like this, please call our office!
Feline Tooth Resorption
According to information presented at the American Veterinary Dental Forum, if your cat is over five years old, there is a 72% chance he or she has a painful feline odontoclastic resorptive lesion (FORL). These dental resorptions once called cat cavities or neck lesions can occur in any tooth. The most commonly affected teeth are the lower premolars.
Unlike cavities in humans, which are the result of bacterial enzymes and acids digesting the teeth, the cause of FORLs is unknown. Specifically, cells known as odontoclasts are found in the defects causing the tooth structure to dissolve. What triggers this reaction has not been determined for certain but a reaction to plaque on the teeth seems to be the major factor.
Cats affected with FORLs may show hypersalivation, oral bleeding, or have difficulty chewing. A majority of affected cats do not show obvious signs but are in pain. A cotton tipped applicator applied to the suspected FORL causes pain with jaw spasms when the FORL is touched.
The FORL can present in many stages — initially (Stage I) an enamel defect is noted. The lesion is usually minimally sensitive in because it has not entered the dentin. Therapy of this defect usually involves thorough cleaning, polishing, and smoothing the defect with a dental drill.
In Stage 2, lesions penetrate the enamel and dentin. These teeth may be treated with glass ionomer restoratives, which release fluoride ions to desensitize the exposed dentin, strengthen the enamel, and chemically bind to tooth surfaces. The long term (greater than two years) effectiveness of restoration of Stage 2 lesions has not been proven.
X-rays are essential to determine if the lesions have entered the pulp chamber (Stage 3) requiring either root canal therapy or extraction. Here the lesion it is not only painful, but bacteria in the mouth now have easy access to the tip of the tooth root where an abscess can develop. Tooth root abscesses have been well documented as chronic sources of infection that can lead to infections on the heart valves, in the liver, kidneys, spleen, joints, bones and central nervous system.
In Stage 4 FORL, the crown has been eroded or fractured. Gum tissue grows over the root fragments leaving a sometimes painful bleeding lesion upon probing. Treatment requires extraction of the root fragments if they appear inflamed or painful to the patient.
At least monthly examine your cat’s mouth for FORLs. Take a Q-tip and gently place it against the area where the tooth meets the gum. If there is pain or bleeding a trip to the veterinarian is in order. Your best friend will thank you.
|COMMON PRESENTATION OF FELINE FORL LESIONS|
These are examples of FORL lesions and what the corresponding dental radiographs look like!
One of the most painful and frustrating conditions cats can develop is feline stomatitis. The cause is unknown, but appears to be a severe reaction to plaque and the tooth structure itself, or the basement membrane of the periodontal tissues. Clinical signs include severe chronic gingivitis, with or without the following: faucitis, pharyngitis, or palatitis (inflammation of the throat or roof of the mouth). Other signs include excessive salivation, reluctance to eat, bleeding gum tissue, extreme oral sensitivity, and weight loss or anorexia. Diagnosis is based on clinical signs and biopsy of the affected gingival tissue. The histopathology usually finds abundant lymphocytes, plasmacytes and occasional neutrophils. Although many organisms have been cultured or found in affected cat’s mouths, none has been proven to be the cause. As such, oral culture and sensitivity or viral isolation has been of little benefit. One recent interesting relationship is that of Bartonella sp. with chronic feline diseases such as gingivitis, stomatitis, and conjunctivitis. The test for Bartonella is available and if positive, the recommended treatment is Azithromycin, an antibiotic given once daily for 21 days. Bartonella sp. have zoonotic potential and thus are important from a public health standpoint.
Case management of a cat with stomatitis should include CBC, full chemistry profile, urinalysis, T4 and free T4, FeLV and FIV testing, gingival biopsy, and Bartonella serology. Cleaning the teeth, homecare/brushing, oral antibiotics and corticosteroids are helpful initially, but their effectiveness for treatment usually wanes within 3-6 months. The only treatment thus far shown to have long-term results without the need further medication is either caudal or full mouth dental extraction. In the only study to report long term results of caudal or full mouth extractions, 60% had significant improvement, another 20% had some improvement, and a final 20% had little to no clinical improvement in the gingivitis, but we have seen that most seem to be more comfortable. Dental radiographs are essential when performing these extractions to ensure the entire root of every extracted tooth is removed. Post-operatively, antibiotics are given for 14-28 days. Pain management is paramount in these patients and is accomplished with pre-anesthetic opioid administration, intraoperative local anesthetics (Bupivacaine), and postoperative NSAID and opioid given orally for at least 5-7 days. For those patients with anorexia prior to presentation, nutritional support via esophagostomy or gastrostomy tube may be warranted either pre or post-operatively until eating well again. Additionally, A CO2 or therapy laser may be used to treat inflamed tissues and decrease pain. In addition, a home care program is begun. The client is instructed how to brush their cat’s teeth daily, followed by irrigation with .2% chlorhexidine. Re-evaluation at one month should show some improvement, and further follow-up at three months should be indicative of success of treatment. If there is little to no response, the remainder of the teeth may need to be extracted or dental radiographs taken to ensure all tooth/root remnants have been removed and that there are no areas of reactive alveolar bone borders.
The question that consistently arises is “How can these patients eat without their teeth?” The fact of the matter is that the ones who respond favorably do tremendously better without the oral pain and chronic infection eating soft food than they ever did before, and those who still have inflammation seem to be more comfortable. Many continue to eat dry kibble even without teeth!
COMMON APPEARANCE OF FELINE STOMATITIS LESIONS
Dental Homecare Recommendations
It is very important to your pet’s health to receive regular dental home care just as you take care of your own teeth. Animals have no special ability to resist dental disease. Please read the following guidelines to help assist you in achieving a successful dental home care program for you and your pet.
Step 1: Examine and Touch the Mouth, Teeth, and Gums
The first step is to make it fun and relaxing for your pet. Use lots of praise and start slowly. Begin by offering a small amount of flavored pet toothpaste on your index finger as “a treat” daily for 5-7 days. This conditions your pet to expect a treat when they see the tube of toothpaste.
Step 2: Brushing or wiping the Teeth with Pet Toothpaste
After this initial introductory period, as you give the paste; use your index finger to rub the teeth and gums in small circles, the same motion as a toothbrush. Continue this for 5-7 days. Once your pet becomes comfortable with this, then progress to a soft bristle brush and continue the same routine. You may want to offer a small amount of the paste before and after brushing as a reward. Some pets will require daily brushing, while others can be maintained by brushing a few times a week.
*** Human toothpaste is not meant to be swallowed and should NOT be used on your pet.
Step 3: Mouth Rinses
Pets with advanced periodontal disease or pets that will not allow brushing may also benefit from an antiseptic oral rinse. These rinses are not as well liked as the flavored toothpastes and will not remove plaque as well as brushing, but they will help reduce plaque bacteria.
Step 4: Treats
There are products that have been proven in clinical trials to reduce plaque and tartar accumulation. Look for the Veterinary Oral Health Council (V.O.H.C.) Seal of Approval on products to ensure that are beneficial for your pet’s dental health.
*** Avoid hard treats such as real bones, hard plastic bones, and cow hooves as they can lead to broken teeth.
Step 5: Diets
Specially formulated diets are available that help reduce plaque and tartar build-up. ROYAL CANIN diets have added chemicals that retard the mineralization of plaque to tartar, thus making the teeth easier to keep clean. Other diets such as Hill’s Prescription t/d diet works mechanically to “brush” the teeth when chewing. The t/d diet can be fed as the sole diet, or as treats.
If you find you cannot perform dental home care on your pet, and you want to keep your pet healthy and avoid bad breath and dental disease, you MUST seek professional treatment more frequently! For most pets a professional cleaning once a year is adequate. Pets with pre-existing dental disease and those lacking dental home care will need professional care more often.
Heart disease in cats is caused most often by a condition known as cardiomyopathy. In this syndrome, the muscles of the heart become unable to perform normally. As cardiomyopathy progresses it may lead to heart failure (inability of the heart to circulate blood normally through the body) or other serious consequences.
Most heart disease in cats is hereditary. Most cases of heart disease in cats are not linked to lifestyle, diet, or home care. Unfortunately, cardiomyopathy is progressive. Most cases of feline heart disease do not exhibit a strong response to treatment. Although some cats with cardiomyopathy never show symptoms or develop heart failure, others die from the condition.
Cats with mild heart disease often do not show any signs of illness. As the disease progresses, however, symptoms of heart failure may develop rapidly. Symptoms of heart failure include:
1.Difficulty breathing or rapid breathing
5.Decreased appetite and weight loss
6.Some cats with heart disease suffer sudden paralysis of one or both hind
legs. For other cats, the first symptom of heart disease is sudden death.
1.Cardiomyopathy and heart disease in cats are believed to be largely
hereditary. Maine Coons, Persians, and Siamese cats are at increased risk.
2.Mature cats are more likely to suffer from advanced heart disease than young
3.Hyperthyroidism can contribute to and exacerbate heart disease in cats.
4.A diet with inadequate amounts of the amino acid taurine has been linked to
one type of cardiomyopathy in cats. High quality commercial diets in
developed countries are supplemented with taurine. Therefore, diet-related
cardiomyopathy is very rare in developed countries.
Some cats with mild cardiomyopathy never develop symptoms or suffer consequences from the disease. Unfortunately, many others ultimately develop heart failure. Many cats with cardiomyopathy die as a result of the condition.
Cardiomyopathy can cause blood clots to form in the heart and then flow into the rear legs of cats. This leads to sudden paralysis of one or both hind legs. This serious complication is extremely painful and difficult to treat. Many cats are euthanized after suffering this complication.
Cats with heart disease are at increased risk of complications from anesthesia.
Cats with cardiomyopathy have difficulty tolerating stress. They may succumb to stress from heat, car travel, grooming, or veterinary procedures.
Cats with heart disease sometimes die suddenly from acute massive heart failure.
Cardiomyopathy is diagnosed through a combination of physical examination and diagnostic tests including electrocardiogram (ECG), X-rays, and ultrasound (echocardiogram). Blood and urine tests usually are run to evaluate for thyroid disease and other concurrent illnesses.
Some cats with heart disease have a heart murmur that can be detected during a physical exam. Many others, however, exhibit no outward signs of disease. Because of this, many cases of cardiomyopathy are not diagnosed until the disease is advanced.
Cats with heart disease should not be placed in stressful situations. They should not be exposed to extreme heat. Medications are often prescribed to improve the function of the heart. Medications used for this purpose include diltiazem, atenolol, propanolol, enalapril, and benazepril. Cats in heart failure may receive medications such as furosemide (Lasix®) to remove fluid from the lungs. Fluid-filled areas of the chest or abdomen may be drained manually by veterinarians. Small quantities of aspirin may be prescribed to reduce the likelihood of blood clot formation and paralysis of the hind legs. If present, thyroid disease is treated to reduce its effects on the heart. Although some cats show clinical improvement when treatment is implemented, many others do not show a marked response to the treatments listed above. Because of this, treatment of heart disease in cats is often frustrating and unrewarding.
For cats with symptoms of heart failure, success of therapy is based primarily upon its effect on the symptoms. Cats with heart disease require follow-up X-rays and echocardiograms at periodic intervals. Regular blood tests are recommended to assess the function of other organs in the body.
Cats with cardiomyopathy do not tolerate stress well. They sometimes suffer complications during veterinary procedures. Hence, veterinarians are not able to perform full diagnostic evaluations on all cats with heart disease.
Degenerative Valvular Disease
Chronic degenerative valvular disease is a rare acquired heart disease in cats. Also known as endocardiosis or myxomatous valvular degeneration, degenerative valvular disease is more common in older small breed dogs. Males appear to be at an increased risk of developing a potentially more severe form of the disease.
The atrioventricular valves (AV valves) separate the top and bottom chambers of the heart. They are composed of leaflets and supporting structures (chordae tendineae) that attach the leaflets to the papillary muscles. The mitral valve is located on the left side of heart and is affected in ~60% of cases with the tricuspid valve (right side of the heart) solely affected ~10% of the time. Approximately 30% of cases involve both AV valves. Rarely the disease affects the aortic and pulmonic valves.
Lesions associated with the disease include: redundant valve leaflets, lengthening of the chordae tendineae, and thickened/fenestrated valve leaflets. This is due to one layer of the valve tissue thickening while another area is degenerating. As a result, blood leaks back in the wrong direction, the atrium (top chamber) increases in size and volume, the ventricle (bottom chamber) gets larger, the leak gets worse, atrial pressure increases, and congestive heart failure results (see congestive heart failure client education for a detailed description).
Elevated pulmonary artery pressure, also known as, pulmonary hypertension, develops in a subgroup of dogs with degenerative valvular disease. This is usually mild to moderate, occasionally requiring medical intervention. Dogs with severe pulmonary hypertension are typically symptomatic showing exercise intolerance, syncope (fainting), or even right heart failure (fluid accumulation around the lungs or in the abdomen). Severe pulmonary hypertension carries a grave prognosis and an associated poor quality of life.
Common clinical signs seen with advanced valvular disease include coughing, labored breathing, syncope, and/or a distended abdomen. Physical exam findings conveyed to pet owners by their veterinarian may include a heart murmur, an extra heart sound or gallop, an irregular heart rhythm (arrhythmia), abnormal pulse quality, and/or abnormal lung sounds (i.e. crackles).
Treatment ranges from no medications in the asymptomatic stages to various classes of drugs aimed to decrease pressures within the heart in advanced stages. These drugs include diuretics, vasodilators, and positive inotropes (see congestive heart failure client education for a detailed description). Prognosis is largely dependent on the underlying stage of the disease. Cats may remain in the asymptomatic class for years. Average life span with conventional therapy (i.e. diuretic and an ace inhibitor) once in heart failure is ~1 year. Recent studies suggest with the addition of newer drugs, average life span may surpass 1.5 years.
A small number of the most common conditions that we see are presented below. There are many other significant dermatological diseases that are not presented. If your cat has a skin condition you are concerned about please call our office for an appointment!
Flea Allergy Dermatitis (FAD) & Other Ectoparasites
Flea allergy dermatitis is one of the most common skin conditions in cats. Signs are often seasonal with warm weather but can be year round here in California. Skin lesions include itchiness, raised red nodules, crusting, red inflamed skin and hair loss. These lesions are most commonly found on the tail head, lumbar area, back of the thighs, and abdomen. Other skin problems like other allergies, infections, and external parasites may present with similar lesions. Often visualization of fleas and their excreta can be seen to aid in the proper diagnosis. In some allergic animals the effects of flea bites may last for weeks.
Treatment includes flea control for all animals within the household with an adulticide flea control product. In heavily infested environments fleas may continue to “emerge” for many months. In these environments a flea control product with an insect growth regulator (IGR) may be considered. Finally, the house and yard may also need to be treated to reduce the flea population. Cats with FAD should have a monthly flea control applied on a year round basis in California. If the itching is severe, injectable or oral corticosteroids are used to prevent self trauma and if infection has already occurred antibiotics will also be needed.
This disease is caused by an infestation by the ear mite Otodectes cynotis. This is a small mite that lives on the skin surfaces and in the ear canals.
Typically, there is a moderate to severe accumulation of dark brown/black waxy discharge from the ear canals. Often the ears are extremely itchy to the pet and frequent scratching and rubbing is noted. The scratching often results in secondary excoriations and ear canal infections with hair loss around and on the ears. Chronic head shaking and scratching can result in an ear hematoma (see below) or blood blister in the ear flap.
Ear mites are usually easily diagnosed by swab or direct visualization by our videootoscopes. Treatment includes cleaning of the debris from the ear canal with cleansers, antiparasitic medications, and often medication to treat secondary infections and the itchiness. It is important to treat all animals in the home and even any recently
Feline Scabies & Walking Dandruff (Cheyletiellosis)
Feline scabies is a highly contagious skin disease caused by a mite called Notoedres cati. This mite tunnels through the skins superficial layers and causes an intensely allergic reaction. This mite is common in multiple cat homes and catteries. The resulting skin lesions and self-trauma result in dry, crusty skin that is most commonly noted on the ears, head, face, and neck. In chronic untreated cases the lesions may affect the entire body. Successful treatment involves treating all affected animals with topical therapeutic shampoos and antiparasitics. Diagnosis is based on superficial skin scrapings and microscopic identification of adult mites, nymphs, and eggs
Cheyletiellosis or walking-dandruff is caused by another mite named Cheyletiella. These do not burrow in the skin, but live on the hair/fur and chew on the skin to feed. This mite is less common than scabies and also most commonly occurs in multi cat homes and catteries. Again itchiness may be mild to severe and affected individuals appear to have and excessive dandruff appearance. All cats in the environment should be treated as for scabies.
Ringworm or dermatophytosis is due to an infection of the hair and skin with a fungus. This infection occurs in cats and dogs, but is most commonly seen in kittens and long-haired cats such as Persians.
The skin lesions may be local, multiple, or involving the entire body. Infection usually results in circumscribed areas of mild hair loss and scaling, itching may or may not be present. Some hairs may appear broken and “stubbled”. Some long-haired cat may be asymptomatic carriers of this disease.
Diagnosis is usually by fungal culture, biopsy, or microscopic examination of the hair (rarely useful). In one form of the disease, caused by Microsporum canis, approximately 50% of the infected hairs will fluoresce green with ultraviolet light.
Treatment for focal lesions may be accomplished by clipping the area and daily topical application of antifungal shampoos and medications. If the lesions do not respond to the topical treatment or the infection is more generalized oral antifungal medications and topical shampoos are used. Treatment orally and topically can be lengthy and should be continued until negative recheck fungal cultures are negative. Finally, this is a contagious infection and all animals should be treated and all handlers should use meticulous hygiene.
Feline acne is a common disorder of hair follicle skin development and excessive gland development. Skin lesions that occur on the chin and lower lip and consist of “blackheads” commonly known as comedones and sometimes a deep hair follicle or skin infections. Treatment consists of clipping the area, warm compresses, topical medications, and antibiotics if infection is present.
Feline Eosinophilic Plaque
Eosinophilic plaque is an inflammatory response most likely a results of a hypersensitivity or allergy to fleas, food, or the environment (atopy). This is a common feline disorder and is especially noted in young to middle-aged cats.
This disease manifests as individual to multiple well demarcated thickened, reddened, and ulcerated plaques. These lesions are generally very itchy and are most commonly observed on the ventral abdomen and inner or back of the thighs. Occasionally, Eosinophilic disease may also occur in the mouth of some cats.
Treatment includes attempting to identify and treat any underlying allergies, antibiotics if infection is present, and usually some form of corticosteroid for variable periods of time until the lesions are resolved. The overall prognosis is variable amongst individuals. Cats with underlying allergies which are controlled long term have a good prognosis. On the other hand, cats with recurring lesions where no underlying etiology is identified often require longer periods of treatment and may become more difficult to treat with time. A prompt diagnosis and treatment will often result in more optimal outcome. We have found, at The Village Veterinary Hospital that these lesions also respond well to a course of treatments with our therapy K-laser.
These are of common clinical presentations of cats with Eosinophilic granulomas
Uses for Laser Therapy
We use a class 4 therapy laser, which is the most effective therapy laser on the market today. Some of the many uses of laser therapy include:
- Arthritis (Degenerative Joint Disease)
- Back Pain (Intervertebral Disc Disease)
- Trauma (Skin, Muscle, Bone)
- Open or necrotic non-healing wounds (Trauma)
- Surgery (Incisions, Growth Removals, Bone Surgery)
- Inflammatory Conditions:
- Acute or chronicotitis (Ear problems)
- Anal Gland inflammation
- Periodontitis (Gingivitis)
- Hot Spots
- Lick Granulomas
- Idiopathic Cystitis (Bladder Inflammation)
- Sinusitis, Rhinitis (Nasal problems)
- Provide a new and non-invasive option for pain management