J i r s p e c t i v e s O n C a t s A N ew sletter f o r C at F anciers F rom T h e C ornell F eline H e a lth C enter Fall 1984 C o m m o n C a u s e s, T r e a t m e n t, a n d P r e v e n t i o n o f F e l i n e G u m D i s e a s e Linda Jorgensen, D.V.M. Feline gingivitis (inflammation of the gums) is a frequently encountered and often very frustrating problem both for the cat owner and the veterinarian. It has many causes. Some causes, such as bad teeth, are easily treated; others, however, require extensive diagnostic and therapeutic measures just to reduce the severity of the problem. Mild gingivitis is well tolerated by the cat, and only the most observant owner w ill be aware of its presence. The signs of severe gingivitis are readily apparent and include ptyalism (drooling), halitosis, and pain or difficulty in eating. Examination of the mouth reveals reddened, swollen, and sometimes ulcerated gums which may be painful or bleed when touched. Causes of Gingivitis Dental disease: A common and easily treated form of gingivitis results from the accumulation of plaque and tartar. Dental plaque is the layer of proliferating bacteria entrapped in food debris and saliva that coats the tooth. Dental tartar or calculus develops when the plaque mineralizes. Extension of plaque and tartar beneath the gums causes inflammation, resulting in redness and swelling. Professional teeth cleaning and the removal of loose teeth are necessary to restore health to the gums. Dental cavities can be a significant problem in the cat. Unlike humans, cats most often develop tooth decay just beneath the gum margins, thus causing gingivitis as well as holes in the teeth. Unfortunately, the process of decay is usually so far advanced when the condition is recognized that tooth extraction is necessary. Some cats seem particularly prone to the development of cavities and require good oral hygiene measures (to be discussed later) to help prevent tooth loss. Broken teeth with exposed pulp cavities may develop tooth root abscesses. Swelling of the gums surrounding the tooth and abscessation of the cheek area overlying the tooth root may result. A swelling or abscess just under the eye often indicates a tooth root abscess. Tooth extraction and treatment with antibiotics is usually curative. If neglected, the infection may extend to the bones of the jaw. Bone infections (osteomyelitis) are difficult to treat and can be dangerous to the cat's overall health. Viruses: Several viruses can cause gingivitis and ulcers in your cat's mouth. The most important of these are feline herpesvirus (rhinotracheitis), calicivirus, and feline leukemia virus (FeLV). Associated with upper respiratory disease, calicivirus and herpesvirus can also cause severe oral ulcerations. These viruses may persist in the cat's body, causing recurrent gingivitis and upper respiratory disease. Feline leukemia virus suppresses the body's natural defense mechanisms, rendering the cat susceptible to numerous infections, including gingivitis. Gingivitis related to FeLV infection can be especially resistant to treatment.
P e r s p e c tiv e s O n C a ts 2 Medical cure of viral diseases is s till not possible. Therefore, treatment generally involves the use of antibiotics to prevent secondary bacterial infections. Some cats require antibiotic treatment indefinitely. These cats have contagious diseases and exposure to other cats should be avoided. Squamous cell carcinoma: Squamous cell carcinoma (SCC) is a malignant tumor which may affect the gums or oral mucous membranes. Affected tissues may look more like ulcers than the lumps caused by most tumors. Pain when eating and halitosis are frequent consequences of the tumor. Biopsy is necessary for accurate diagnosis. Surgical removal and/or radiation therapy are the current methods of treatment. Left untreated, SCC w ill slowly progress to the point where no treatment is effective. Pemphigus: Pemphigus is a disorder of the immune system affecting the skin and mucous membranes. Ulceration of the skin, anal, and genital mucous membranes, as well as ulcers of the gums and mouth, may be seen. At one time, many forms of pemphigus were invariably fatal. Now, although the disease is s t ill serious, its effects can usually be well controlled with the use of steroids or gold-containing drugs, both of which decrease inflammation. Biopsy and special staining techniques are used to diagnose pemphigus. Eosinophilic granuloma complex: The eosinophilic granuloma complex (EGC) causes raised and sometimes ulcerated red or orange-colored areas of the skin, gums, and oral cavity. The cause of the disease is unknown but it does not appear to be contagious. Diagnosis is made by biopsy. Treatment with steroids or progesterone hormones is often effective but some forms respond poorly. Radiation therapy may be effective in resolving cases resistant to medical treatment but can only be used when a solitary lesion is present. Plasma cell glngivltis-pharyngitis: Plasma cell gingivitis is a disease causing accumulations of plasma cells, a component of the immune system, in the gums and oral cavity of the cat. Like EGC, the cause is unknown. Affected areas are glistening and ulcerated, and have an irregular, cobblestone surface. Response to treatment is variable. Antibiotics, antiprotozoal drugs, steroids, progesterones, and immune system modulators have been used with limited success. Recently, goldcontaining drugs have shown promise in treating this condition. Systemic diseases: Severe kidney disease and diabetes mellitus are sometimes associated with gingivitis and oral ulceration. Cats suffering from these diseases are often obviously very i l l and need prompt treatment. If the underlying disease can be controlled the gingivitis usually resolves. This is not a complete list of the causes of feline gingivitis but it does include those most commonly encountered. The cat owner who is aware of these diseases is more likely to recognize a problem when it exists and to seek veterinary care. Diagnosis and Prevention Like any disease process, gingivitis is easiest to treat when diagnosed early. Examining your cat's mouth each month is helpful in this regard. Your veterinarian can demonstrate how this can most easily be done. All cats with significant gingival disease should be examined by a veterinarian. If the cause of the problem is not immediately obvious (e.g., bad teeth) diagnostic testing may include blood counts, blood chemistry evaluation, FeLV testing, bacterial cultures, and biopsies. Virus isolation cultures for calicivirus and herpesvirus are costly but may be valuable to breeders with many affected cats. Periodic professional teeth cleaning reduces the contribution of dental disease to gingivitis. Owners may then help keep ( C o n t i n u e d o n p a g e 8. )
3 F e l i n e A d v i s o r y C o u n c i l W e l c o m e s N e w M e m b e r s Six new members have been appointed this year to the Cornell Feline Health Center Advisory Council, representing a broad segment of the cat world. We are happy to welcome: Joan M. Arnoldi, D.V.M., President of the American Association of Feline Practitioners Nancy A. Bull, President and Managing Publisher of Veterinary Practice Publishing Co. Roger Caras, noted author and Special Correspondent on Animals and the Environment for ABC News Mark L. Morris, J r., D.V.M., Trustee and Research Vice President of the Morris Animal Foundation Mordecai Siegal, TV talk show personality and award-winning author numerous books and columns on pets Joan Wastlhuber, Abyssinian breeder, Cat Fanciers' Association (CFA) Shorthair Judge, and President of the Robert H. Winn Foundation for Cat Research. Perspectives On Cats A Newsletter for Cat Fanciers From The Cornell Feline Health Center T h e ultim ate purpose of th e C ornell Feline H ealth C e n te r is to im prove th e health of cats everyw here, by developing m ethods to prevent or cure feline diseases, and by providing continuing education to veterin arian s and cat o w n ers. All co n trib u tio n s are taxdeductible. Director: Fredric W. Scott, D.V.M., Ph.D. Editor: Joyce Tumbelston Secretary: Sheryl A. Bronger Special Consultant: Leo A. Wuori, D.V.M. 1984 by C ornell U niversity on behalf of the C ornell Feline H ealth C enter, College of V eterinary M edicine, Ithaca, NY 14853. All rights reserved. Perm ission to reprin t selected p ortions m u st be obtained in w riting. C ornell University is an equal opportunity, affirm a tive action educator and employer. Feline Advisory C ouncil members pictured at their A nnual M eeting in June. From left: Dr. Joan Arnoldi, Ellen Yanow, N ancy Bull, Joan W astlhuber (seated), Mordecai Siegal (seated), Dr. Theodore Rude, Dr. Mark Morris. of Each w ill serve a term of three years, assisting the Feline Health Center in developing long-range goals, gaining financial support, and making our work known to the public. Other members are: George W. Abbott, Animal Hospital John M. Brentlinger, Sally Faile El-Sayed D.V.M., Angell Memorial Jr. Jean Holzworth, D.V.M., Animal Hospital Angell Memorial Hazel Lindstrand, Burmese, Persian, and Maine Coon breeder, CFA Shorthair Judge Rosemonde Peltz, M.D., cat breeder, Former CFA Board Member Theodore A. Rude, V.M.D., Assistant to the President of Salsbury Laboratories Ellen Yanow, Executive Director of Tree House Animal Foundation. Representing the interests of cat owners, cat breeders, animal shelters, the veterinary profession, scientific community, and pet-related industry, the Council provides a balanced outlook and valuable suggestions. The Feline Health Center is privileged to have these dedicated people contributing their skills and talents to help make a better world for cats.*
P e r s p e c tiv e s O n C a ts 4 A n s w e r s t o Y o u r Q u e s t i o n s A b o u t F e L V Nearly half of the letters and phone calls from anxious cat owners to the Cornell Feline Health Center are about feline leukemia (FeLV). Little is known about the disease by most people until it strikes, and for good reason it is widely feared. Following are some of the most frequently asked questions, and answers prepared by specialists here. 1. What is feline leukemia? Feline leukemia (FeLV) is a highly contagious viral disease of cats which has many manifestations. 2. What are the signs? There are many possible signs of FeLV, because the disease can take many forms. Some common signs caused by the virus itself are: jaundice; depression; weight loss; decreased appetite; diarrhea or constipation; blood in the stool; enlarged peripheral lymph nodes; respiratory distress; decreased stamina; excess drinking or urination; fetal resorption, abortion, or in fe rtility; "fading" kittens; and a syndrome resembling panleukopenia ("cat distemper"). FeLV also interferes with the cat's natural ability to fight disease, so almost any severe, chronic illness may lead your veterinarian to suspect FeLV. 3. How Is the disease spread from cat to cat? FeLV is shed in the saliva and possibly the urine and feces of infected cats. Prolonged, extensive cat-to-cat contact is required for spread, because the virus is rapidly inactivated by drying. 4. Is there any cure? To date, there is no cure for feline leukemia. A variety of chemotherapy regimes have been used, and in some cases these w ill result in a temporary remission, depending on the condition of the cat and the type of leukemia that is present. These drug therapies may allow the cat to continue in a reasonably healthy state for a period of a few weeks to a few months. However, it must be realized that these are only remissions and not permanent, lifelong cures. Drugs that are used are very potent and must be monitored carefully so as not to overdose the cat. 5. Can massive doses of Vitamin C cure feline leukemia? To date, no one has done a controlled study to prove efficacy of Vitamin C in curing cats of leukemia. Controlled studies against feline viral rhinotracheitis, canine distemper, and human respiratory infections have failed to show efficacy of high doses of Vitamin C. Of course, a multivitamin supplement and mineral supplement might be helpful to any sick animal in order to help that animal ward off the infection it is suffering. However, there is little evidence to support the cure of any of these conditions with these vitamins. Other than providing general support to the animal's health, vitamin supplements w ill not be effective in preventing the spread of this virus within a cattery and certainly w ill not cure individual cats. 6. If there is no cure for FeLV, why did my veterinarian prescribe steroid treatment? Treatment with a steroid, such as prednisolone, is "immunosuppressive"; that is, it tends to decrease numbers of circulating white blood cells (lymphocytes). A cat with leukemia may have an increased number of abnormal lymphocytes circulating in its bloodstream; therefore steroid treatment may help to combat the disease. Prednisolone may also act directly against the cells of solid white blood cell tumors (lymphosarcoma) that can be caused by FeLV. The steroids also inhibit the
5 reticuloendothelial system, which destroys old red blood cells, and this effect may help combat the anemia and excessive red blood cell destruction that so often accompany FeLV. However, because these drugs can only act against lymphocytes that have matured, and not against the infected, immature white blood cells in the bone marrow, the disease eventually overcomes the benefits of steroid therapy* It is important also to remember that, because both steroids and FeLV suppress the immune system, the cat under prednisolone treatment is especially vulnerable to other infections. 7. When w ill there be a vaccine? Extensive research on this disease has led to the development of at least two experimental vaccines which are currently being field tested. It w ill be a while, perhaps several years, before the testing program has been completed and approval is granted by the U.S. Dept, of Agriculture. 8. What do the FeLV test results nean? Two FeLV blood tests are in common use, and interpretation of a positive (or negative) test depends on which test your veterinarian has administered. Both the ELISA test (Leukassay-F, or kit test) and the Immunofluorescent test (Hardy, IFA, or slide test) detect one component (antigen or protein) of the virus particle as it circulates in the blood, either alone in the serum (ELISA) or attached to white blood cells (IFA). However, the virus circulates in the blood (a condition known as "viremia") at two different stages in the disease. The ELISA test can detect the primary viremia - the stage before the bone marrow has become infected, when the cat's natural defenses s till have a chance to control the virus, though they can't eliminate it. The ELISA test can also detect the virus in the secondary viremia stage - when the virus is in the bone marrow and thus has established a "firm foothold" within the cat. In contrast, the IFA test can first detect circulating virus at the secondary stage; if the disease process has gone this far, it has passed the stage where the body can hope to control it. A ll cats that test positive by the IFA tests, as well as most of those that are ELISA-positive, are secreting virus in the saliva and are infectious to other cats. A negative test does not imply immunity to FeLV, and it does not te ll whether or not the cat was once exposed to and infected by the virus. A negative test w ill be found in a cat that (1) has never been exposed to FeLV (which is what we all hope for), (2) is incubating the virus at an earlier stage than either test can detect (this cat might test positive later on), (3) has contained the virus and has not become persistently viremic, and (4) was infected with the virus previously and developed solid tumors but no longer has the virus in the blood. 9. I got two different test results for my cat. Hhat does this mean? This is an all-too-common problem. As explained above, both the IFA and the ELISA tests determine the presence of leukemia virus in the blood of cats, but at different stages in the disease. If the cat is positive by ELISA and negative by IFA at the same time, it may merely be that the virus is at the primary viremia stage which ELISA can detect and IFA cannot. A cat might also test differently at two different times with the same test; a reversal of a positive test to negative eight weeks later is especially common for the ELISA test. This indicates that the cat has successfully contained the early spread of the virus, so that it never reaches the secondary stage of viremia. It is also possible for a cat in the early stages of the disease to tes! IFAnegative and become positive later on. Once a cat has become IFA-positive, it is usually positive for life. Wherever there is a discrepancy, one must repeat the tests to be sure that consistent results are obtained. F in a lly, when two t e s t s f a i l to agree,
P e r s p e c tiv e s O n C a ts 6 there is a slim possibility that one of them was wrong. This is not something to base all your hopes upon, but it is true that the tests are not 100% accurate, and once in a great while you might get an incorrect result. 10. Should a ll FeLV-positive cats be euthanized? Euthanasia is the only effective method for virus control, because FeLV-positive cats are usually shedding virus in their saliva. In some cases, healthy cats may repeatedly test ELISA-positive and IFAnegative, and these do not appear to shed virus; however, there is no guarantee that some later stressful situation w ill not cause them to start shedding virus, or that they w ill not someday become i l l. If you own only one FeLV-positive cat, euthanasia is not necessary from the standpoint of control of disease transmission, as long as you keep the cat away from all others; but remember that in time the cat may become so uncomfortable that euthanasia becomes the only humane course of action. 11. My cat had a positive FeLV test, but she seems completely healthy. H ill she become sick and die? Even if two or more successive tests reveal your cat to be truly positive, she w ill not necessarily die. An FeLV-positive, healthy cat may live for months or years; it is impossible to predict. However, over 60% of "healthy" FeLV-positive cats die within two years of leukemia or an FeLV-related disease. Your cat is probably shedding virus that could infect other cats, and you should take precautions to reduce the chance of disease spread (see below). In addition, the body's reaction to the virus may protect her from the primary leukemia/lymphosarcoma problems but not from the immune suppression that the virus also causes. She w ill thus be much more susceptible to other contagious diseases and w ill require careful watching and immediate treatment if she should become i l l. 12. How long can a cat survive with feline leukemia? A cat with FeLV disease, given the best available chemotherapy and steroid treatment, may live for several weeks to several months, depending on how advanced the disease is at the time of diagnosis. However, it is impossible to te ll how long any particular cat can be kept in remission. 13. Can a cat become immune to FeLV? A very high percentage of adult cats that are exposed to the virus w ill develop immunity to the primary viral disease and w ill not be persistently viremic. Usually these cats live out a normal life span. However, the virus is s t ill sequestered somewhere in the body, and could possibly break out and cause disease at a later date when the cats are stressed. 14. Can I or my children become infected with FeLV if our cat has it? Hhat about my dog? There is no documented evidence that feline leukemia virus can be transmitted to humans. True, FeLV can be grown in human culture cells; the same is true of many other things that don't cause disease in man. Although cat-to-human transmission cannot be ruled out 100%, there certainly is no substantiated evidence that it does occur, despite extensive research. The only persons that might possibly be at risk are those whose immune defense systems are impaired (by chemotherapy, for instance) or extremely young infants. But again, there is no evidence of this having occurred. There is similarly no evidence that the feline leukemia virus is carried by or causes any illness in dogs. 15. One of my cats was just diagnosed as having leukemia. How can I protect my others from getting the disease? In either a cattery or a multicat house-
7 hold, the most effective procedure is to test by IFA and remove all FeLV-positive cats. The premises should be thoroughly scrubbed with detergent or disinfectant and wiped down with a solution of four 0 2. of Clorox per gallon of water; this is an excellent disinfectant for viruses and other infectious agents. Scrub and disinfect all food bowls, water bowls, bedding material, and litte r pans. Better yet, replace them with new ones. The remaining cats should be retested every three months or so for the next eight to twelve months, and any that become positive should be euthanized. The household cannot be considered "free" of infectious FeLV until all cats test negative in two tests at least three months apart. No new cats should be brought into the household until all cats already there test negative repeatedly, and only new cats that themselves test negative should be introduced. In addition, the new cats should be isolated for three to five months and retested negative once or twice more before they are allowed to mingle with the others. If you have only a few cats and are reluctant to euthanize a positive one, particularly if it is apparently healthy, a strict quarantine program may permit you to protect your other cats from the disease. The FeLV-positive cats should be given the old food, water, and litte r dishes, and new dishes should be purchased for the healthy, FeLV-negative cats. All Positive cats must be prevented from having any contact with the negative ones. Cats with FeLV should also be kept indoors, both to reduce the danger that they w ill be exposed to other diseases their weakened bodies w ill not be able to resist, and to reduce the danger of infecting neighborhood cats with FeLV. i6. My one and only cat just died from FeLV. Is it safe to bring a new pet into my home? Feline leukemia virus is relatively unstable, and w ill not survive outside an infected cat for any appreciable length of time. The Cornell Feline Health Center recommends a period of at least 30 days (and even up to 90 days) following removal of an infected cat from a household before a new cat is introduced, just to be absolutely certain that all virus in the home has died. The other precautions that should be taken are identical to those described above to protect healthy cats: eliminate and replace the food dishes, litte r pans, and bedding that were used by the infected cat. Floors that are covered with tile or other hard surfaces should be cleaned and then disinfected with the dilute Clorox solution (four oz. Clorox to one gal. water). Thorough vacuuming of rugs, plus the one month quarantine, should be sufficient to eliminate the virus from the carpeting in the household. 17. A favorite breeding queen (now pregnant) has tested positive for FeLV. Must she be euthanized? If so, can I wait until after her kittens are born? FeLV is transmitted from carrier queens to their kittens either in utero or after birth. A very high percentage of kittens born to infected queens w ill succumb to FeLV infection or FeLV-related diseases. It is absolutely essential that you establish a test-and-removal program so that all persistently infected animals (those that remain FeLV-positive for more than three to four weeks) are removed from the cattery. To continue to breed FeLVpositive queens is merely expanding the problems and in essence signing the death warrant of kittens born to those queens. 18. What is the Cornell Feline Health Center doing to fight FeLV? Our research on feline leukemia has involved basic studies on the virus itself, attempts to develop vaccines to prevent the disease, and attempts to develop methods of immunotherapy. Research continues in each of these three key areas in the hope that definitive answers will be found, eliminating forever the threat of this fatal disease.
P e r s p e c tiv e s O n C a ts 8 G u m D i s e a s e the cat 's teeth clean by gently rubbing the surface of the teeth with a soft cloth soaked in dilute hydrogen peroxide or salt water. This should be done daily if possible. Toothpastes for humans should not be used as the foaming frightens animals and swallowed toothpaste can cause gastrointestinal upsets. Feeding of dry food helps prevent the formation of tartar. Dry food can be fed to cats who do not suffer from concurrent feline urologic syndrome. If you are aware of the problem of gingivitis and you are willing to periodically examine your cat's mouth and keep his or her teeth clean, you w ill prevent most cases of gingivitis from getting out of control. Regular attention to your cat's mouth w ill also enable you to recognize when a veterinarian's assistance is necessary, so that early treatment can be initiated.* L i n d a J o r g e n s e n ( U. C. D a v i s '7 9 ) i s a r e s i d e n t a t t h e C o r n e l l U n i v e r s i t y S m a l l A n i m a l C l i n i a. H e r s p e c i a l i n t e r e s t i s i n t e r n a l m e d i c i n e. C a t C l u b s : W e T h a n k Y o u Once again, we'd like to express our thanks to three very special cat clubs special because they are staunch supporters of the Cornell Feline Health Center. Since the last issue of "Perspectives" went to press, we have received contributions from: Brooklyn Cat Fanciers Liberty Trail Cat Fanciers Massachusetts Colony Cat Club, Inc. Each of these clubs has previously contributed to our feline health studies, and we are deeply grateful for their tradition of support. If possible, we would like to encourage more clubs to follow in their footsteps. One way in which several clubs stand with us is by donating a portion of their show proceeds. We w ill gladly supply "Awards of Distinction" to be presented to the winners; clubs can then donate the amount that otherwise would have been spent on trophies. If your club may be interested, please write to us. Cornell Feline Health Center Cornell University College of Veterinary Medicine Ithaca, New York 14853 Flower Library Schurman Feline Health Center