CORNELL FELINE HEALTH CENTER NEWS

No. 4 August 1981

Central nervous system disease in the cat Brian A. Summers, B.V.Sc., M.Sc., Ph.D.

Fortunately for cats and their owners, disorders of the central nervous system (CNS) in the feline occur only sporadically. The brain and spinal cord are quite unique tissues and their diseases are difficult to treat. Furthermore, the capacity for regeneration and repair in the CNS is limited and consequently many animals (and people) who suffer CNS injury or disease are left permanently incapacitated. Congenital CNS disorders are uncommon in the cat. For example, hydroceph­ alus, which is quite common in certain breeds of dogs, is rarely encountered in the cat. The Manx cat, however, does show a predisposition to spina bifida of the lumbosacral vertebrae and associated changes in the spinal cord (menin- gomyelocoele) may occur. Furthermore, workers at Cornell have associated teratogenic effects with the administration of griseofulvin to pregnant cats. Cyclopia, exencephaly microphthalmia and optic nerve hypoplasia were found. Accordingly, the administration of any drug to the pregnant queen should be with extreme caution. Panleukopenia virus, the cause of infectious feline enteritis, can attack the brain of kittens in utero. Such animals are born with a cerebellar disorder, manifested by dysmetria and tremor once the kittens begin to ambulate. Some animals can compensate reasonably for their defect but, as alluded to above, their brain damage is permanent. Nutritional disease and associated CNS injury are rare but thiamine deficiency may produce an encephalopathy in the cat (and many other species) . Usually this is a result of the destruction of this vitamin by thiaminases of dietary origin (fish). Commercial foods for cats generally provide adequate Bi and this condition is now less commonly encountered. Affected cats may be incoordinated, convulsions may occur, and handling the cat will often induce it to ventroflex the head and neck and roll up into a ball. Early therapy with thiamine may cure this disorder. The most common feline CNS disorders are infectious and involve a spectrum of pathogens. Toxoplasmosis is caused by the protozoan organism Toxoplasma gondii. Occasionally this agent will produce a necrotising encephalomyelitis in the cat. Injury to the CNS is severe and the condition is frequently fatal. Cryptococcosis may affect the feline and produces a disseminated meningo- encephalomyelitis. The organism responsible is a yeast, Cryptococcus neoformans, (Cont. on page 2) Cornell Feline Health Center News page 2

CNS diseases (Cont. from page 1) and again symptoms and pathological cerebellar involvement. Siamese cats changes are severe. are often victims of these disorders but cases in common domestic short A third killer which produces hair cats are seen also. inflammation of the meninges and adjacent brain and spinal cord is the Feline ischaemic encephalopathy is coronavirus of feline infectious a syndrome in the cat somewhat akin to peritonitis. Although predominantly stroke in man. Onset of disease is affecting tissues of the abdominal peracute and is caused by focal cerebral cavity, FIP can involve the nervous ischaemia. Usually seen in mature system with lethal outcome. cats (often in midsummer, curiously enough), it can be expressed by Symptoms for the last three depression, circling, incoordination, conditions mentioned may include or seizures. These acute signs often depression, incoordination, paralysis, resolve in a few days, leaving a seizures, and so on. Interestingly, permanent change which may be behavioral, all three may extend from the CNS to visual, or other. The cause of this the eye, producing a chorioretinitis. disorder is not known. Rabies may produce encephalomyelitis CNS diseases associated with aging in the cat, as in many other animal are occasionally encountered in the species. Fortunately, feline rabies feline. A primary degenerative disorder is documented relatively infrequently. of the spinal cord, myelopathy, has Recently workers in Alabama recorded recently been described in the cat. A the presence of a polioencephalo- similar condition occurs in large myelitis in cats. One or two examples aging dogs such as the German Shepherd. of this emerging disease have been recognized at Cornell also. Finally, tumors occur in the feline CNS and are not uncommon. Meningioma Finally, to complete the spectrum, constitutes the most common primary larvae of the fly Cuterebra will (Cont. on page 4) occasionally gain access to the brain in cats. Apparently these larvae burrow in from the poll region, as signs are referable to cerebellar- medullary injury. The parasite CORNELL FELINE HEALTH CENTER wanders around in the tissue, producing NEWS severe injury. Happily, this bizarre A publication of situation occurs infrequently. Cornell Feline Health Center NYS College of Veterinary Medicine Storage diseases occur in all Cornell University, Ithaca, NY 14853 species and constitute an important group of metabolic disorders. The ©1981 by Cornell Feline Health Center, Ithaca, NY. All rights reserved. Permission to reprint basis of the disorder is an enzyme selected portions must be obtained in writing. deficiency and so the patient stores (in various tissues) metabolites that Director/Fredric W. Scott, D.V.M., Ph.D. cannot be handled by normal catabolic Assistant Director/Leo A. Wuori, D.V.M. Administrative Aide/Edna H. Morusty pathways. Editorial Assistant/Joyce Tumbelston Clinical disease is often a reflection of CNS involvement, as The ultimate purpose of the Cornell Feline Health Center is to improve the health of cats these cells (neurones) are incapable everywhere, by developing methods to prevent of replacement and are soon impaired. or cure feline diseases, and by providing con­ These disorders are inherited and tinuing education to veterinarians and cat symptoms, first seen around one to owners. All contributions are tax-deductible. three months of age, often reflect the Cornell Feline Health Center News page 3 Diagnosis of virus infections in cats Richard C. Weiss, V.M.D., Ph.D.

Virus infections constitute the with FeLV are more susceptible to FIP), most important group of infectious and immune status (proper vaccinations, diseases affecting the cat. Viruses adequate intake of colostrum or "first are submicroscopic particles, i.e., milk" after birth, administration of they cannot be observed by the immunosuppressive drugs which may ordinary light microscope, and consist impair resistance to disease, etc.). of proteins and nucleic acids (e.g., Viruses may attack almost any organ DNA or RNA). of the cat and produce a variety of Unlike bacteria and most other clinical syndromes, including respira­ life-forms, viruses require living tory disease (conjunctivitis, rhinitis cells to "stay alive." In fact, out­ or sinusitis, laryngitis, bronchitis, side the living cell, viruses appear and pneumonia); enteric disease (gastro­ crystalline-like, almost mineral in enteritis, dysentery); diseases of the structure. Once these inert particles blood, bone marrow and lymph glands invade cells they acquire the ability (leukemia, lymphosarcoma); disease of to incorporate the essential building the central nervous system (encephalitis, blocks of life, amino acids and meningitis); and generalized or systemic proteins (which are made, free of diseases (e.g., peritonitis). charge, by the cell itself), and may The diagnosis of specific viral reproduce themselves countless times. infections based on clinical symptoms Unfortunately, the cell (or entire alone is frequently difficult, as the organism, if the virus infection is same symptoms of disease may result severe enough) may be destroyed during from the effects of other microbial the process of viral invasion. agents (e.g., bacteria, fungi, myco­ Although cats are frequently plasma, protozoa), parasites, toxins infected by viruses without showing or chemicals, allergies, and cancer. signs of disease, there are several In addition to clinical signs, important viruses of cats that are diagnosis of viral infection may be commonly associated with disease. made by the veterinarian on the basis These include feline panleukopenia of one or more of five methods: virus (distemper, feline enteritis); rabies virus; herpesviruses (feline 1. Viral isolation in tissue rhinotracheitis, pseudorabies); feline culture or eggs. In this method, swabs calicivirus; feline infectious periton­ of infected secretions (oral, nasal, itis virus (FIP); and feline leukemia ocular, rectal) or small pieces of virus (FeLV, feline leukemia). tissue are added to tubes containing living cells. The cells are then grown In general, whether or not an in the laboratory under proper condi­ individual cat will develop disease tions of temperature, carbon dioxide following infection with any of these and acid levels which simulate the viruses depends on many factors, natural body environment. The cells are including age (kittens are frequently examined after several days. If virus very susceptible to viral infections, is present in the samples, the cells particularly when they did not suckle undergo characteristic changes which the queen after birth, and are also are recognized by the virologist. quite vulnerable around weaning time), genetic background, nutritional status, 2. Histopathology. Tissues from environmental stresses, coinfection deceased animals or tissues taken from with other viruses (e.g., cats infected (Cont. on page 4) Cornell Feline Health Center News page 4

Diagnosis (Cont. from page 3) the animal during surgery (biopsy) are (Method 2) . fixed in formalin (a chemical preser­ Diagnosis of specific feline viral vative), sectioned, and observed under respiratory diseases (e.g., rhinotra­ the light microscope for typical viral- cheitis vs. calicivirus infection) induced cellular changes recognized requires isolation of the virus in by the pathologist. cell culture, and/or demonstration of 3. Serological methods for identi­ a specific antibody response (Method 5). fication of virus or viral protein. Even with all the available tech­ Numerous tests identify virus in niques, diagnosis of viral infection cells by using antibodies which react may be extremely difficult, since there specifically against the virus (e.g., may not be enough viable virus particles direct fluorescent antibody test). in the sample to yield a positive test, 4. Electron microscopy. The or the virus itself will not grow in electron microscope can magnify virus the laboratory. This has been the particles 100,000 times or greater major problem for many years with FIP and is used to examine tissues, diagnosis; diagnosis of FIP depends secretions, and cell cultures for virus primarily on typical clinical signs, particles. In this method, many virus histopathology (Method 2), and an particles must be present in the sample elevated FIP antibody titer (Method 5). in order for them to be seen. This is The recent development of new and more a fairly rapid but relatively insensi­ sophisticated tests by virus researchers tive technique for viral diagnosis. will certainly increase the chances of accurate diagnosis by the veterinarian 5. Demonstration of specific of FIP and other important feline antibody response against the virus viral diseases. (antibody titer). Antibodies against the virus are measured at the outset of disease and again at 10 days to Dr. Richard C. Weiss (U.P. '73) two weeks later, if possible, to completed his Ph.D. in Veterinary demonstrate a rise in the antibody Virology at Cornell in May, 1981. levels. Examples of this method include the indirect fluorescent antibody test and the serum neutralization test. In general, the particular method(s) CNS diseases (Cont. from page 2) used depends on which viral disease is neoplasm, while lymphosarcoma, which suspected. For example, for diagnosis may be seen at any age, is the other of FeLV, a blood test that identifies important diagnostic consideration. certain proteins associated with the Meningioma produces depression, circling, virus (Method 3) is usually used in and seizures, while paralysis, often conjunction with clinical signs, referable to spinal cord involvement, although biopsy of the lymph nodes and is more typical of lymphosarcoma. examination of blood, tissue, and fluids for malignant cells (i.e., Dr. Brian A. Simmers, Assistant cytology) may also be required. Professor of Pathology, earned his Diagnosis of panleukopenia is B.V.Sc. at the University of Melbourne, frequently made on the basis of clinical Australia, in 1969. He received his signs and blood counts, but may be M.Sc. from the Royal Veterinary College, confirmed by examining feces for viral University of London, in 1972 and particles by EM (Method 4), virus completed his Ph.D. at Cornell in 1980. isolation in cell culture (Method 1), Dr. Summers is a Member of the American and/or histopathology of intestine College of Veterinary Pathologists. Cornell Feline Health Center News page 5 Geographical distribution of feline infectious peritonitis (FIP)

J.E. Barlough, D.V.M.; J.C. Adsit, B.A.; F.W. Scott, D.V.M., Ph.D.

Feline infectious peritonitis (FIP) occurrence in countries reporting is a unique coronaviral disease of their presence. Some of the major domestic and exotic cats characterized findings of this survey are summarized by fibrinous peritonitis and/or pleur- briefly below: itis, or formation of disseminated pyogranulomas, or both. It was first Brazil - 2 cases out of 700 diseased definitely described in 1963 by Dr. cats examined (University of Sao Jean Holzworth at the Angell Memorial Paulo) Animal Hospital in Boston. Chile - Not diagnosed

Later reports indicate that cases China (People’s Republic) - Frequency of FIP have apparently been observed unknown since the early 1950s, although they had not been previously recognized as Colombia - Approximately 8 cases of representing a separate disease entity. effusive FIP per year (National In the United States, FIP has been University of Colombia, Bogota) seen in the Midwest since at least Egypt - Frequency unknown 1962, in the New York City area since 1956, and in California since 1954. Ghana - 1 suspected case in the past 5 years (Department of Veterinary Following the initial clinico- Services, Kumasi) pathologic descriptions of FIP in the United States, clinical reviews and Guatemala - Not diagnosed case reports began to appear in many India - Not diagnosed areas of the world. Literature reports of FIP in numerous countries have Iraq - Not diagnosed appeared, including Australia, Austria, Italy - Approximately 4-5 cases per Belgium, Canada, Denmark, England, year (Universities of Perugia, Finland, France, Germany, Iran, Ireland, Torino, Bologna, and Milan) Israel, Japan, Mexico, the Netherlands, New Zealand, Norway, Scotland, Senegal, Kenya - Not diagnosed South Africa, Sweden, Switzerland, and Nigeria - 1 case in the past 5 years Yugoslavia. (Ahmadu Bello University) In an attempt to supplement avail­ Norway - 15-20 cases in the past 2-3 able literature information regarding years (Veterinary College of Norway) the geographical distribution of FIP, the Cornell Feline Health Center in Papua New Guinea - Not diagnosed 1980-81 conducted an international, Poland - Not diagnosed survey of veterinary and agricultural college faculty members, diagnostic Romania - Not diagnosed laboratory and agricultural ministry Saudi Arabia - Frequency unknown personnel, and veterinary investiga­ tional laboratory researchers.1 Scotland - Infrequently diagnosed (University of Edinburgh) Questionnaires sought information concerning the presence or absence of Sweden - Frequency increasing; 10-20 effusive and non-effusive FIP, and cases per year (Uppsala) their approximate frequency of (Cont. on page 8 ) Cornell Feline Health Center News page 6

Making Euthanasia Easier on Clients

LOS ALTOS, Calif.— Eu­ zine “an excellent means of in­ starting the program, he adds thanizing a pet isn’t a pleasant forming pet owners about vet­ that the feeless procedure is experience for the client or the erinary medicine.” also “good for the ego—it’s veterinarian. But the practi­ While Dr. Weyker may good to hear someone say tioner who insists on payment charge an office fee to diag­ you’re a nice guy.” for the procedure, especially if nose a moribund patient be­ In addition. Dr. Weyker be- it’s a hefty sum, can not only fore euthanizing the animal, lieves such programs result in exacerbate grief, but positive- he says in most cases, even beneficial overall publicity for ly alienate a client as well. this fee isn’t charged. If a cli­ veterinarians, perhaps even doing more for the profession There is an antidote to this ent comes in to have an ani­ than, for example, media sticky situation: suggest the mal put to sleep and the re­ spots sponsored by associa­ client make a donation to a mains disposed of, there's tions that picture the practi­ charitable foundation for ani­ “never a charge.” tioner in a good light.| (W mals instead of paying a fee. He’s convinced that this thing is clear, lie stresses, One doctor who has taken last act of “compassion” is a “squeezing bucks out of peo­ this tack sees it as a positive practice builder. ple for euthanasia is not the practice builder, in addition Checks of euthanasia rec- way to improve the veterinary to providing the more intangi­ ords 10 or more years old- before the contribution pro­ image. ble benefit of letting him feel gram began—have shown “Even the local newspaper, like a “good guy."______that most of these clients nev­ which is generally anti-profes­ Dr. Howard A. Weyker, at er returned. In contrast. Dr. sion, has printed several unso­ the Los Altos Animal Clinic Weyker says many clients licited articles about our eu­ here, has given his clients the who have made contributions thanasia donations and por­ charitable contribution choice have either returned with trayed veterinary medicine in since 1974. When an animal is their new pets or generated re- a very favorable and respect­ euthanized at Los Altos, the ferral business.______ful manner,” says Dr. Wey­ staff expresses its sympathy Some practices in this area ker. and suggests, in place of a eu­ Dr. Weyker also gives one- thanasia fee, a $20 tax-de­ charge up to $50 for the “pit­ tance” it costs to euthanize an year subscriptions to Today's ductible donation to the Ani­ Animal Health to clients who mal Health Foundation. The animal, says Dr. Weyker, while only a few sporadically surpass $100 in paid fees for foundation supports animal the year. The first complimen­ health research and publishes offer the contribution alterna­ tive. At the same time, he tary issue is accompanied by a a bi-monthly magazine, To­ pre-printed note citing the day’s Anim al Health, which is notes that clientele at most of the practices has “dwindled” practitioner as the gift sub­ sent free to the donor for a scription source. The sub­ year. while his has “steadily” in- creased. scriptions cost the practition­ Today’s Animal Health is er $3 each. run by a volunteer board of “We have a happy clientele, But Dr. Weyker says client veterinarians and is aimed at and I think our success has re­ response to the gift subscrip­ informing animal owners volved around our euthanasia tions, instituted three years about responsible animal program,” says Dr. Weyker. ago, hasn’t been nearly as Never keen on charging eu- ownership and health care. “dramatic” as the reaction to Dr. Weyker calls the maga­ thanasia fees even before the euthanasia program. ■

Reprinted from the April 1981 issue of DVM, THE NEWSMAGAZINE OF VETERINARY MEDICINE, by permission of Gridley Publications, Inc. (Emphasis added.) Cornell Feline Health Center News page 7

Let Our Memorial Gifts Program Work For You As the preceding article shows, you can develop client loyalty, Cornell Feline Health Center build better public esteem for the New York State Veterinary College Cornell University profession, and enlarge your practice Ithaca, New York 14853 through referrals by grateful clients, when you participate in a memorial gifts program. IN MEMORI AM What's more, your memorial gift to the Cornell Feline Health Center will help support critical research The enclosed check for $ is given in memory of on deadly feline diseases.

There are two ways you can pet's name age breed participate in the Cornell Feline

Health Center memorial gifts program; O w ner: (1) Instead of collecting a euthanasia and/or disposal fee, you can suggest Address: that your client contribute directly to the Cornell Feline Health Center; or (2) You can surprise your client by collecting the fee as usual and Please acknowledge this gift in my name. then forwarding it to the Cornell

Feline Health Center. Your client Veterinarian: will be deeply moved to receive a sensitive acknowledgement from us Address: explaining what you have done in memory of the deceased cat. Personally and professionally, you will reap great rewards as you Would this client like to receive our publications? give through this program. Just fill □ yes □ no out the form below and mail it today for your supply of memorial donation cards (pictured at right).

□ Please send a supply of donation cards for the euthanasia memorial donation program. I | Other comments ______

Name

Address

City______State______Zip______CORNELL FELINE HEALTH CENTER; N.Y.S. College of Veterinary Medicine; Cornell University; Ithaca, N.Y. 14853 Cornell Feline Health Center News page 8

FIP (Cont. from page 5) Cleaner litter boxes Turkey - Infrequently diagnosed The following practice tip appeared (Ankara University) in the January 1981 issue of The California Veterinarian. It is Uganda - Not diagnosed reprinted here with permission from Venezuela - Infrequently diagnosed the editor. (University of Zulia, Maracaibo) "We eliminated the smell and source of Yugoslavia - Infrequently diagnosed; contamination over ten years ago. Our non-effusive form seen (University hospital has used Mobilfoam trays for of Zagreb) pre-packaging (TF-0850 10"x5/8") as the container in which we place one Zambia - Not diagnosed handful of Vermiculite . Vermiculite Zimbabwe - Infrequently diagnosed is a soil expander which can be pur­ (Ministry of Agriculture) chased at any nursery supply store. The trays can be supplied by your ^Barlough, J.E., Adsit, J.C. and paper goods distributor. The cats Scott, F.W.: The worldwide occurrence generally adapt well to the use of of feline infectious peritonitis, the disposable system. Occasionally (submitted for publication) they spread the light Vermiculite about the cage. The Vermiculite is very inexpensive compared to litter Dr. Jeffrey E. Barlough (Davis '79) is and weighs one-tenth as much and is studying for his Ph.D. in Veterinary highly absorbent and not dusty." Virologys with emphasis on the oat 's immune response to feline infectious - Dr. Barry L. Rathfon, Director peritonitis (FIP). AAHA Member Hospital Jean C. Adsit is a microbiology tech­ Davis Animal Hospital nician at Cornell. She holds a B.A. Davis, California in Biology from the State University College at Potsdam, N.I. Dr. Fredric W. Scott (Cornell '62; Ph.D.3 Cornell ’68) is a Professor of Virology at the N.I.S. College of Veterinary Medicine and Director of the Cornell Feline Health Center.

Cornell Feline Health. Center New York State College of Veterinary Medicine CORNELL UNIVERSITY ITHACA, N.Y. 14853