Feline Health Topics for veterinarians

Winter 1990 Volume 5, Number 1

Feline Bronchial Diseases

Bronchial diseases are characterized by airway more completely. Diagnosis is complicated further obstruction and increased airway restriction. The because more than one disease can be present in a basic anatomy of the ’s may patient (i.e. and ). actually make it more susceptible to bronchial diseases than other animal species. Those anatomical Coughing and dyspnea are typical hallmarks of differences include an increased number of bronchial diseases, however these signs can indicate seromucous bronchial glands (especially in older other conditions (see Table 2). When with all cats) and a thick bronchial wall which is capable of forms of bronchial disease are grouped together and increasing the constriction of the bronchial lumen. compared to a control group, cats most predisposed to bronchial diseases are middle-aged cats (2 to 8 Feline bronchial diseases have previously been years old), female cats and Siamese. In the 65 cases grouped together and frequently called felin e studied at Cornell, the signs noted by owners were: bronchial asthma or chronic bronchitis. Based on a coughing (88%), dyspnea (39%), wheezing (20%), Cornell study, feline bronchial diseases are not all the sneezing (23%), and vomiting (15%). Duration of same and should be subclassified. A proposed the disease is variable. A seasonal incidence was not classification is presented in Table 1. However, more substantiated statistically. clinical and diagnostic studies are required to develop specific criteria to describe feline bronchial diseases Diagnosis Patient History:

Inside this issue.. Complete and accurate patient history is a useful aid in diagnosis. Answers to the following questions provide clues as to the type of bronchial disease Feline Bronchial Diseases page 1 present:

Proceedings from Canine and Feline How long has the owner been aware of the Reproduction Symposium page 6 problem? The duration of the problem determines if Mark Your Calendar page 6 the disease is chronic (persisting months to years) or subacute (less than 24 hours) or stages in-between. Subject Index page 7 Is coughing productive or nonproductive? Job Opportunity page8 Coughing which produces gagging or spitting up may be indicative of an infection such as bronchitis. Feline Health Topics 2

Does cat have trouble breathing? Does the cat bronchial cytology and culture and thoracic snore or sneeze? Is there nasal or ocular discharge? radiographs. If practical, pulmonary function tests Wheezy or noisy breathing are manifestations of would be ideal in diagnosing bronchial diseases. lower respiratory diseases; whereas sneezing, snoring, Bronchial Cytology!Culture: Transtracheal nasal and ocular discharges are characteristic of upper washing provides cells and fluid from the lower respiratory diseases. airways for cytologic and culture evaluation. A Physical Exam: sample can be obtained by transtracheal aspiration, endotracheal tube bronchial brushing or Observe the cat’s breathing before doing the bronchoscopy. physical examination since the stress of physical contact can cause an increased respiration rate. Cytologic examination of a tracheal wash shows Respiration rate (normal 20-60 per minute), dyspnea, a mucoid exudate with various cell types present, but depth and regularity should be noted. If dyspnea is with an absence of parasite larvae or ova. The Cornell observed, does it occur on inspiration or expiration? study identified the predominant cell types as Inspiratory dyspnea occurs in restrictive diseases eosinophilic (24 percent), neutrophilic (33 percent), such as , , or neoplasia. macrophagic (22 percent), and mixed population of Expiratory dyspnea occurs in obstructive diseases cells (21 percent). Bacterial cultures were positive in such as bronchitis, , severe pulmonary 24 percent of the cats. edema or asthma. Also, the respiratory pattern provides more diagnostic information. Small rapid breaths are typical of restrictive diseases; deeper slower breaths occur with obstructive diseases. C \ Auscultation of the heart and aids in Feline Health Topics detecting cardiac abnormalities (murmurs and arrhythmias) and pulmonary abnormalities. Late A publication for veterinary professionals inspiratory crackles (sound resembling a crackling The ultimate purpose of the Cornell Feline Health Center is to fire) are heard in restrictive pulmonary diseases. improve the health of cats everywhere, by developing methods Early expiratory crackles are audible in obstructive to prevent or cure feline diseases, and by providing continuing education to veterinarians and cat owners. All contributions are diseases. If wheezing occurs on inspiration, tax-deductible. Director: Fredric W. Scott, D.V.M., Ph.D. extrathoracic obstruction, such as laryngeal paralysis, Assistant Director: John E. Saidla, D.V.M. is the cause. Wheezing during expiration occurs in Editor: Ju n e E. T uttle Secretaries: Sheryl A. Thomas, Gwen Frost, intrathoracic obstruction. Phyllis Dague

This publication is made possible, in part, by {Note: Inaccurate thoracic auscultation can occur a grant from 9-Lives Cat Foods. We grate­ fully acknowledge this interest and support if the cat is purring. A technique that has worked in the furthering of feline health. This successfully in the Small Animal Clinic at Cornell acknowledgement of our gratitude is not an endorsement of any particular company or College of Veterinary Medicine is to turn on a water product. faucet in the examination room for about ten seconds. © 1990 by Cornell University on behalf of the Cornell Feline Health Center, College of The cat w ill stop purring for one to two minutes.) Veterinary Medicine, Ithaca, NY 14853. All rights reserved. Permission to reprint se­ lected portions must be obtained in writing. Diagnostic Tests: Cornell University is an equal opportunity, affirmative action educator and employer. Diagnostic tests to evaluate bronchial disease are 3

Table 1. Preliminary Classification of Feline Bronchial Diseases Asthma Chronic Bronchitis Emphysema

Definition: Reversible obstructed Inflammation of the Long-standing A pathological airway marked by bronchi which has a short inflammation of the accumulation of air spasmodic contraction of and moderate course. bronchi that is constant in the lungs. Can the bronchi. or characterized by be a sequel to recurrence after periods chronic bronchitis. of quiescence.

Age of Cat: Any age, but tend to be Any age Middle to old age. Any age. young adults. More common in Siamese. Clinical Signs: Episodes of paroxysmal Coughing Coughing, dyspnea, and Coughing, dyspnea, dyspnea, with or without wheezing. and wheezing. coughing and wheezing.

Diagnostic Tests: Radiographs Usually mild to moderate Prominent bronchial Marked bronchial Marked bronchial prominent bronchial pattern (variable severity). pattern with interstitial pattern with pattern; during episodes of infiltrates frequently overinflation, dyspnea overinflation may present. Collapse of (’"histopathology is occur. right middle lobe most conclusive is common. Patchy test) alveolar densities. Overinflation may be present.

Bronchial Cytology/Culture Eosinophil is primary cell Macrophages or Neutrophil is primary Neutrophil is type. Cultures are usually neutrophils predominate. cell type, although primary cell type, negative. Most common bacterial eosinophils can be although species cultured are present. Cultures may eosinophils can be Pasturella multocida, be positive for bacteria present. Cultures Bordetella bronchiseptica, or mycoplasma. may be positive for or alpha hemolytic bacteria or Streptococcus sp. mycoplasma.

Prognosis: Good. Excellent response Excellent. Responds well Poor for complete Poor. Damage to to therapy. to antibiotics if caused by recovery. Requires the lungs is bacteria. constant treatment. irreparable.

Results can differentiate between allergic or bronchitis, or parasitic lung disease. The eosinophilic infectious diseases. In the normal cat there w ill be or neutrophilic exudates occurred more frequently in small amounts of mucus, columnar epithelial cells, cats with moderate to marked bronchial disease. The a few macrophages and occasionally neutrophils. macrophagic exudates were more commonly A marked increase of neutrophils can indicate a associated with mild bronchial disease. bacterial, viral, mycoplasmal or fungal , bronchitis, tumors, foreign Radiography: Thoracic radiography will identify bodies or aspiration . An increase in and distingush between thoracic , eosinophils is characteristic of asthma, allergic extrapulmonary diseases impairing lung inflation, Feline Health Topics 4 primary pulmonary disease and cardiovascular Thoracic radiographs show large numbers of par­ disease. allel linear shadows radiating toward the lung periphery or ring shadows with small radiolucent Accurate reading requires knowledge of thoracic centers. These structures are thickened bronchial anatomy, skilled interpretation, and proper technique. walls. Air trapping or emphysema is characterized The following are guidelines to obtaining good by lung overinflation which causes flattening of the thoracic radiographs: diaphragm, scallop appearance of the diaphragm, • Use the shortest exposure time appropriate for expansion of the rib cage, and pronounced separation the film/screen combination in use. If possible of the heart and diaphragm. Persistent thickening of choose a detail film for exposure. the bronchial w all and hypertrophy of the pulmonary arteries may develop. « Set X-ray machine at 200-300mA at 52-70 kVp. Other useful tests which w ill assist in a diagnosis to preclude other diseases with similar signs include •Expose the film at the peak of inspiration. Vas­ heartworm test and fecal flotation. cular structures are more easily identified and vessel wall margins are more sharply defined Treatment during inspiration. The main objectives of bronchial disease therapy ♦ Recommended projections include either a right include relief of reversible obstruction, control of or left lateral and either a ventrodorsal or dorsov- cough and secretion, elimination and prevention of entral projection. infections, control complications, and avoidance of stress factors.

Table 2. Differential Diagnosis of Coughing and Dyspnea Drugs that enhance the bronchodilation (i.e. increase in intracellular cyclic aden­ Asthma Pectus excavatum osine monophosphate) are Allergic bronchitis Pulmonary infiltrates effective in treating broncho- of eosinophils constrictive diseases. Drugs and recommended dosages Bronchiectasis are listed in Table 3.

Acute viral or bacterial infection Cardiac failure In emergency cases of Chronic bronchitis Pleural effusions dyspnea, administer with glucocorticoids, a Mycotic pneumonia Mediastinal masses bronchodilator, and/or a sym­ pathomimetic drug. Most cats Parasitic pneumonia Pneumothorax respond in fifteen to thirty Pulmonary neoplasm Feline infectious peritonitis minutes.

Desquamative alveolitis CNS disorder For long term treatment, bronchodilators can be given Interstitial fibrosis Foreign body daily or used at the time of bronchial respiratory distress. Laryngeal edema or paralysis If an allergy or hypersensitiv- 5

Table 3. Drug Therapies for Bronchoconstriction Drug D osage

Sympathomimetic Amines: Epinephrine 0.5 to 0.75 ml 1:10,000 dilution SQ or IM Isoproterenol 0.1 to 0.2 ml 1:5000 dilution SQ or IM Terbutaline 0.625 to 2.5 mg BID or TID orally Methylxanthines: Aminophylline 2 to 5 mg/kg every 8 hours Theophylline elixir 0.1 ml/kg every 6 to 12 hours orally Slow Bid® * 100 mg once daily in the evening Corticosteroids: Dexamethasone 0.2 to 1.0 mg/kg IV Prednisolone sodium succinate 1 to 3 mg/kg IV or IM Methylprednisolone acetate 0.5 mg/kg IM Prednisolone 2.5 mg orally Oxygen: As needed with humidification

* Per Dr. Brenda McKiernan, University of Illinois

ity is the cause for the disease, then oral prednisolone Acknowledgment: Special thanks to Dr. N. Sydney is used at the minimum dose that achieves a good Moise, assistant professor of medicine, and Dr. response. Administering a long-acting steroid (meth- AmyDietze Yeager, assistant professor of radiology, ylprednisolone acetate, 10 to 20 mg IM ) can be useful for reviewing this article. when a client is unable to pill his/her cat. However, References: such treatment should be avoided in the long term because it suppresses the adrenal-hypothalamic axis Moise NS. Dietze AE: Bronchopulmonary diseases. In The Cat: Diseases and Clinical Management, Churchill Livingstone. New York, NY (775-817), and may cause iatrogenic hyperadrenocorticoidism. 1989.

Bacterial infections are treated with antibiotics Moise NS, Spaudling GL: Feline bronchial asthma: Pathogenesis, pathophysiology, diagnostics and therapeutic considerations. Comp Contin which have been selected based on culture and Educ Prac Vet 3:1091-1102, 1981. sensitivity tests. Cats respond well to ampicillin (11 Moise NS, Wiedenkeller D, Yeager AE, et al: Clinical, radiographic, and to 22 mg/kg TID orally) or amoxicillin (11 to 22 mg/ bronchial cytologic features of cats with bronchial disease: 65 cases (1980- kg BID orally). Tetracycline (20 mg/kg TID oraly) is 1986). Joum Amer Vet Med Assoc 194(10): 1467-1473, 1989. the preferred drug to use if a mycoplasmal infection Moses BL, Spaudling GL: Chronic bronchial diseases of the cat. Vet Clin is present. ■ NA/SmaU Anim Pract 15(5):929-948, 1985. Noone KE: Pulmonary hypersensitivities: Feline bronchial asthma. In Current Veterinary Therapy IX, WB Saunders Co., Philadelphia, PA. (287- 289), 1985. Feline Health Topics 6

Proceedings from Canine and Feline Reproduction Symposium Published in a Book The proceedings from the First International These papers summarize the most current research on Symposium on Canine and Feline Reproduction the normal reproductive processes in dogs and cats (1988) have been and the extent to which their fertility can be enhanced, published in the suppressed or controlled. There are five papers that hardcover book, are specifically on feline reproduction (premature “Dog and Cat gonadal failure, effect of light manipulation on ovarian Reproduction, Con­ and hormonal activity, effect of melatonin on traception and photoperiod and coital responses, effects of Artificial Insem­ pharmacological suppression of prolactin, and cryo- ination”. The 29 preservation and embryo transfer). The book also papers are arranged includes 13 abstracts of posters. into sections on Veterinarians interested in canine and feline ovarian function, induction of estrus fertility management and reproductive scientists will and ovulation, con­ find this book a useful reference. The 350-page book costs $90 and can be ordered from: Journals of traception, normal partuition and drug-induced termination of pregnancy, and artificial insemination Reproduction & Fertility Ltd., P.O. Box 32, Commerce Way, Colchester C02 8HP, Essex, United Kingdom. ■

Mark Your Calendar for Second Annual Feline Specialist Seminar

The week-long indepth seminar will be held August 6 to 10 in Ithaca, NY. Topics for this year's program include feline urological syndrome, dentistry including feline cervical lesions, hematology, anemia, leukemia, chemotherapy, behavior, nutrition, flea products (including environmental control), anesthesia, intensive care, and identification of pain and its relief. There w ill be over 30 hours of lecture and 20 hours of laboratory sessions.

This seminar w ill provide one of the best, intensive learning opportunities available anywhere. The registration fee is $300. For further information contact Mrs. Linda Ritzier, Conference Coordinator, Office of Continuing Education, College of Veterinary Medicine, Cornell University, Ithaca NY, 14853 or call (607)253-3200. ■ 7

Subject Index

Anesthetics/Drugs: Feline Hyperthyroidism, June ’82 A Guide to Feline Anesthesia, Spring ’84 Update on Hyperthyroidism, Vol 1(1) Cats and Pharmaceuticals, Summer ’84 Treatment for Hyperthyroidism, Vol 1(2) Synopsis of Cardiac Drugs, Vol 1(2) Fluid Therapy: Using Organophosphates to Control Fleas, Vol 1(3) Basic Principles of Transfusions, Vol 1(4) Side Effects of Megestrol Acetate Therapy, Vol 2(2) Telazol: A New Injectable Anesthetic, Vol 2(3) Gastroenterology Effects of Xylazine on Cardiac Function, Vol 2(4) The Impact of Fecal Impactions, Vol 2(1) Isoflurane: A New Inhalant Anesthetic, Vol 2(4) Hepatic Diseases: Bacterial Diseases: Feline Hepatic Lipidosis, Vol4(3) Campylobacter jejuni and Cryptosporidia: Two New Causes of Feline Diarrhea, Winter ’83 Cats and Tuberculosis, Summer ’83 Hospital Management: Cat Scratch Disease, Fall ’83 Virucidal Disinfectants, Vol 1(3) Salmonella Implicated as Cause Selecting the Right Suture Material, Vol 2(1) of Songbird Fever, Vol 3(3) Neurology: Behavior: Central Nervous System Disease in the Cat, Aug ’81 Feline Behavioral Problems, May ’81 Autonomic Polyganglionopathy, Spring ’83 Peripheral Vestibular Diseases, Fall ’84 Cardiology: New Cardiovascular Studies, June ’82 Oncology: Feline Heartworm Disease, Summer ’85 Phototherapy of Cancer, Winter ’83 Synopsis of Cardiac Drugs, Vol 1(2) A Case for Chemotherapy, Spring ’85 Mammary Tumors Are Third Most Common Cancer Client Relations: in Cats, Vol 1(4) The Veterinarian’s Role in Bereavement, Oct ’82 Effect of Radiation and Chemotherapy on Wound Healing, Vol 4(2) Dermatology: Ophthalmology: Eosinophilic Granuloma, Vol 1(3) A Differential for Oral Ulcers in Cats, Vol 2(2) Intraocular Inflammation in Cats , Winter ’84 Complicated Ulcerative Keratitis, Vol 2(4) Diagnostic Tests and Aids: Parasitology: ELISA for Detection of Feline Coronaviral Antibod­ ies, Nov ’81 Feline Haemobartonellosis, Summer ’83 New Computer Program Aids in Diagnosis, Fall ’83 Feline Heartworm Disease, Summer ’85 Diagnostic Ultrasonography, Winter ’84 Feline Blood Parasites, Vol 2(3) Feline Diagnostic Services at Cornell, Summer ’84 Understanding Coronaviral Serology Titers, Fall ’84 Toxicology: New Computer Program for Veterinarians, Winter ’85 Ethylene Glycol Intoxication in the Cat, Oct ’82 Toxoplasmosis: Interpretation of Serologic Results, A Review of Anticoagulant Rodenticides, Vol 1(3) Summer ’85 Lead Poisoning in Cats, Vol 4(1,2) Heartworm Antigen Test, Vol 1(2) Biopsy Principles, Vol 3(1) Respiratory: Panther Study Provides New Insight into FeLV Eustachian Tube Polyps: A Cause of Chronic Respira Tests, Vol 3(1) tory Distress, Fall ’83 Radiographic Evaluation of the Dyspneic Cat, Win’85 Endocrinology: Management of Diabetes Mellitus in the Cat, Nov ’81 Feline Health Topics 8

Urology: Zoonoses: Micturition Disorders in Cats with Sacrocaudal Cat Scratch Disease, Fall ’83 Vertebral Injuries, Nov ’81 Toxoplasmosis: Interpretation of Serologic Results, Part 1: Understanding FUS, Fall ’85 Summer ’85 Part II: Understanding FUS, Vol 1(1) Chronic Renal Failure, Vol 3(2) Ruptured Bladder and Peritoneal Dialysis in a Cat, Vol 3(4) Job Opportunity The College of Veterinary Medicine has a small Vaccines: Compendium of Feline Vaccines, Fall ’83 animal extension veterinarian position available. Vaccination Recommended for Cats, Fall ’83 This person will answer questions relating to Using the New FeLV Vaccine, Spring ’85 canine and feline species and promote their health Explanation of FeLV Vaccine Guidelines, Summer by interacting with veterinarians, breeders, ’85 Vaccines and Adjuvants, Vol 4(1) owners and the news media. This position will encompass working with the James A. Baker Viral Diseases: Institute for Animal Health, Feline Health Center, Immunopathogenesis of FIP, Feb ’81 Herpesvirus Induced Atherosclerosis, Feb ’81 Veterinary Diagnostic Laboaratory and the New Insights in Gastrointestinal Viruses, Feb ’81 Community Service Practice of the Department Transmission of FeLV, May ’81 of Medicine-Small Animal Clinic. Diagnosis of Virus Infections in Cats, Aug ’81 Geographical Distribution of FIP, Aug ’81 Qualifications for this position are a DVM or Feline Chronic Polyarthritis, Spring ’83 Catpox Virus Infection, Summer ’83 VMD, minimum of five years in a small animal Recommendations for Prevention and Treatment of practice, knowledge of epidemiology, computer Mortality Complex, Spring ’83 skills, and excellent written and verbal Understanding Coronaviral Serology Titers, Fall ’84 Is Feline Leukemia Transmissible to Man?, Fall ’85 communication skills. Those individuals Feline Immunodeficiency Virus, Vol 3(3) interested should contact Dr. Donald Lein, The Immune Response to FIP in Cats, Vol 3(4) Director of the Diagnostic Laboratory and chairman of the search committee, at (607) 253- 3903.

Cornell Feline Health Center Cornell University College of Veterinary Medicine Ithaca, New York 14853

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