Asthma in Cats (Feline Allergic Bronchitis)
Asthma is a hypersensitivity to environmental allergens. This acute respiratory disease in cats resembles bronchial asthma in humans. Feline asthma affects approximately 1 percent of all cats. Siamese may have a slightly increased risk. Some of these cats present as an acute emergency with severe respiratory distress; others have a chronic history of coughing and wheezing. Cats with a chronic cough may need to be distinguished from cats with a hairball problem. In some cats, there will be seasonal triggers, and the asthma will be acutely exacerbated at those times.
In some cases, asthmatic attacks may be triggered by exposure to inhaled allergens, such as tobacco smoke, kitty litter dust, various sprays, and carpet deodorizers. Heartworm may well be a leading cause of asthma. In many cases, the initiating cause is unknown.
An acute attack begins with the sudden onset of difficulty breathing, accompanied by wheezing and coughing. This is associated with a sudden contraction of the smooth muscles surrounding the bronchi. The bronchial tubes are then dramatically narrowed. The wheezing is heard as the cat exhales, and usually it is loud enough to be heard with the naked ear.
During a severe attack, the cat may sit with her shoulders hunched or lie chest down with her mouth open, straining to breathe. The mucous membranes are a bluish color due to the lack of oxygen (cyanosis). Only two other conditions produce similar signs and symptoms: They are pleural effusion and pulmonary edema (see Heart Failure).
Treatment: Immediate veterinary attention is needed to relieve bronchial spasm and ease respiratory distress. Epinephrine may be needed as an emergency treatment. Bronchodilators, such as terbutaline, and cortisone are effective during the acute attack. Antihistamines and cough suppressants should not be used because they interfere with the cat's ability to clear her own secretions. Asthmatic cats may have to be hospitalized for sedation and to remove them from an allergenic environment. Supplemental oxygen, such as an oxygen cage, may be needed for acute cases.
Feline asthma is a chronic condition with recurring attacks. These attacks are often controlled with maintenance doses of an oral corticosteroid. To avoid dependency, the medication is usually given every other day. Some cats may respond favorably to tapering the drug, whereas others experience an immediate relapse and require lifelong medication. If the trigger for the attacks is a seasonal one, such as certain pollens, the cat may only need medication at those times of year.
Many asthmatic cats are now treated with specially designed inhalers, such as Aerokat. Medications prescribed by your veterinarian are administered by having the cat breathe through the inhaler mask. Albuterol (a bronchodilator) and steroids, such as fluticasone, are the most commonly used inhalant drugs. This method minimizes side effects from steroids and provides rapid relief.
Antibiotics are rarely needed, unless the cat has a concurrent Mycoplasma infection.
Try to minimize exposure to the inciting allergens. A HEPA air filter in the house may be useful.
This article is excerpted from “Cat Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.
Copyright © 2008 by Delbert Carlson, DVM, and James M. Giffin, MD. All rights reserved.