Cats may occasionally be affected with a disease referred to as asthma/bronchitis. Asthma causes the airways (bronchi) in the lungs to sporadically constrict. This condition is termed bronchoconstriction, and severely restricts airflow to the lung tissue, causing patients to gasp for air. This is typically manifested by open-mouthed breathing in the cat. Bronchitis causes the airways to become inflamed. This results in some narrowing of the airways, as well as excessive mucus production, which in turn can lead to chronic coughing in addition to difficulty breathing. Most cats have a combination of asthma and bronchitis, so we refer to this as feline asthma/bronchitis complex (FAC/FABC).
The underlying causes of feline asthma/bronchitis are not well-understood. Exposure to airborne allergens is thought to underlie most cases. Perfumes, scented oils or candles, new litter, detergents, house cleaners, pollens and household construction with subsequent exposure to dust and mold have all been implicated. It is uncommon to positively identify the specific offending agent, but it is wise to make an effort to minimize potential exposure in asthmatic cats. Heartworm disease in cats may provoke asthma-like symptoms as well.
Typically cats suffering from asthma/bronchitis have a history of coughing. Coughing in cats is frequently mistaken for hairballs, as cats will exhibit similar behavior when trying to pass a hairball. Similarly, coughing may be mistaken for gagging or unsuccessful attempts at vomiting. Coughing fits may increase in frequency and some cats can develop severe respiratory distress with open-mouthed breathing, which is often referred to as an asthma attack. This can be life-threatening and require emergency treatment with oxygen therapy.
Diagnosis of feline asthma/bronchitis is made by a combination of the history, physical examination findings, chest x-rays (thoracic radiographs), and even transtracheal wash. This is a procedure performed under general anesthesia to collect samples of airway secretions for cytology as well as bacterial culture to rule-out infection.
The mainstay of treatment of cats suffering from asthma/bronchitis is the careful use of corticosteroids (prednisone) and bronchodilators (terbutaline). Inhalers allow some owners to administer other types of medications such as fluticasone (a corticosteroid) or albuterol (bronchodilator). A face mask must be used if an inhaler is prescribed. We are often unable to completely wean asthmatic patients off of corticosteroids, but every effort is made to reduce the dosage to the minimum effective dose. Occasionally, cats may develop a superimposed airway infection that requires antibiotic administration.
Generally, the prognosis for most cases is good with lifelong therapy. Periodic blood testing is recommended to monitor for liver problems as well as for the development of diabetes mellitus (which can happen with some cats taking corticosteroids). Often, the best medicine is removal of the patient from the current environment, however this is typically not practical or even possible in some cases.