Inflammation of the smaller bronchi is called bronchitis. It is characterized by repeated coughing, which further irritates the lining of the tubes and spreads infection to the trachea. The trachea and the bronchi have a protective layer of mucus that traps foreign materials and infectious agents. Along with hairlike cilia that move foreign material toward the mouth, this mucus layer serves as a major defense system against infection. Conditions that interfere with the function of the mucociliary blanket-such as chilling; breathing cold, dry air; and dehydration-predispose a cat to bronchial infection.
Acute bronchitis is most commonly caused by an upper respiratory infection. Secondary bacterial infections are common and frequently lead to persistent cough and chronic bronchitis. The cough of acute bronchitis is harsh, dry, and hacking, and it is aggravated by exertion and cold, dry air. Therefore, warm, humid air and restricted exercise are of great therapeutic value.
Shedding is a cat’s natural process of losing dead hair. Outdoor cats may lose more hair in the spring and fall and retain more fur in the winter, while indoor cats can shed all year round. Regularly grooming your cat and vacuuming hair from your house should minimize the inconvenience of shedding. However, if you see bald patches in your cat’s fur or notice a significant loss of hair, the underlying cause may be a health-related problem and should be investigated by a veterinarian.
Chronic bronchitis refers to bronchitis that persists for several weeks. Many cases begin as acute bronchitis; others occur as a sequel to feline asthma. After a period of chronic coughing, a secondary bacterial infection becomes established. The cough of chronic bronchitis is moist or bubbling and often ends with retching and the expectoration of foamy saliva. This may need to be distinguished from hairballs.
Chronic bronchitis can severely damage the bronchial tubes, and infected mucus and pus can accumulate in partially destroyed bronchi. This condition is called bronchiectasis. Chronic coughing can also lead to a breakdown and enlargement of the alveoli, a condition called emphysema. These conditions are not reversible but can be managed medically in most cases. For these reasons, chronic coughs require veterinary examination and professional management.
Treatment: Rest and humidification of the atmosphere are important. Confine your cat in a warm room and use a home vaporizer. Cough suppressants interfere with host defenses and prevent the elimination of purulent secretions, and they should not be given to cats with chronic bronchitis. Expectorants may help. Bronchodilators (such as Theophylline) relax the breathing passages and reduce respiratory fatigue. Phlegm should be cultured and specific antibiotics selected by your veterinarian.
Cortisone preparations reduce the inflammatory response caused by coughing. However, cortisone is contraindicated in the presence of bacterial infection and should be used only with caution under professional supervision.
WebMD Veterinary Reference from "Cat Owner's Home Veterinary Handbook"