Chronic irritation to the airways is the most common cause of coughing in cats. It is variably called chronic bronchitis, allergic airway disease, allergic bronchitis or asthma. Coughing can be triggered by a cat inhaling irritants such as pollens or dust. It can also be triggered by cigarette smoke, even household cleaning sprays. What happens is the airways respond to the irritant by contraction of the smooth muscle that lines the bronchial tree, to prevent the irritant from moving deeper into the lung. Mucus is secreted to trap the irritant and a cough is triggered to expel it. All of these responses narrow the airways which results in difficulty breathing. Siamese cats appear to be particularly predisposed.
While some cats gradually develop a chronic cough or wheeze others suddenly find it very hard to breath, especially to breath out. They tuck themselves into a position they find easiest to breath from and the speed of breathing increases. Some cats are mildly affected. For others the condition is life threatening. Other diseases such as bacterial infections, foreign bodies in the air passages, heart disease or airway parasites can cause similar clinical signs but an asthmatic reaction is the most common cause of coughing and wheezing in cats.
In most but not all instances a simple x-ray reveals evidence of thickened small airways (bronchi) with air trapped in constricted areas. Sometimes we need to examine with a bronchoscope and take a wash from the airways, a bronchial lavage.
Prevention And Treatment
While we try to determine what triggers asthma – and eliminate it- the constricted air passages are treated with a variety of drugs including anti-inflammatories, bronchodilators and drugs to break down mucus (mucolytics). We advise changing the litter to a low dust type, avoiding all household sprays and restricting cats indoors if asthma attacks occur after going outside. The best way to give an asthmatic cat anti-inflammatory (corticosteroid) is through an inhaler specially designed for cats. The inhaler is tolerated surprisingly well. We think it’s easier to use than giving tablets, and it targets the drug exactly where it’s needed, in the air passages. The prognosis for asthma depends on the severity of the disease and on the time delay before treatment is started. If asthma is allowed to become chronic, irreversible narrowing to the airways, that doesn’t respond to drugs can occur.
Regurgitating hairballs can look like and be mistaken for coughing. Not each attempt to regurgitate a hairball is effective so the lack of hairballs doesn’t by default mean a cat is coughing. Monitor your cat closely. True coughing usually warrants our intervention.