When a pet suffers from asthma, environmental triggers cause a constriction of the bronchi leading from the trachea to the lungs, causing an abrupt and severe breathing difficulty. It is very common in cats (up to one percent of cats are thought to suffer from it), but also occurs in dogs, with small breeds being more likely to suffer the symptoms.
During an asthma attack, pets exhibit shallow and rapid breathing as they attempt to force air through the narrowed airways. Owners may notice wheezing. While dogs naturally pant, open mouth breathing is always abnormal in cats. Breathing difficulty in any pet should be treated as an emergency.
As in people, pets with asthma are treated with a combination of steroids and bronchodilators. Because asthma attacks can be triggered by the environment, pets with asthma should not be in households with smokers, and owners need to be aware of the potential for problems with dusty or highly scented cat litters. Although asthma never goes away, it can be successfully managed.