What is kennel cough?

Kennel cough is inflammation of the trachea and the airways just below it, set off by infection. Vets use two longer names for it, infectious tracheobronchitis and canine infectious respiratory disease, and Cornell's Riney Canine Health Center calls it the most common cause of upper respiratory disease in dogs. The illness is usually mild and clears on its own, but the Merck Veterinary Manual notes that it can progress to pneumonia in puppies and to chronic bronchitis in frail or very old dogs.

The germs vary from case to case. The clinical team at MSPCA-Angell lists Bordetella bronchiseptica, canine parainfluenza virus, canine adenovirus type 2 and Mycoplasma cynos as the most common causes, with canine influenza and distemper less common but potentially more serious. Merck adds that Bordetella, parainfluenza and adenovirus infecting a dog together is the most frequent combination. Cases vary partly because the cause varies, which is why vets so often describe kennel cough as a complex rather than a single disease.

Kennel cough moves through the air and by touch. Cornell lists droplets from coughs and sneezes, direct contact between dogs, and contaminated objects such as food bowls, water bowls and even door handles, and MSPCA-Angell adds hands and clothing. Merck says it spreads rapidly among dogs kept close together, naming veterinary hospitals, daycare, boarding facilities and kennels, and notes that stress and extremes of ventilation, temperature and humidity make dogs more likely to catch it and to get sicker.

The kennel in the name is about crowding, not about kennels alone. Cornell's list of close-contact settings includes grooming facilities, shelters, competitions and dog parks. On Cape Ann that means the fenced Gloucester Dog Park at Stage Fort Park and, from October 1, the off-season beaches, where Good Harbor takes dogs on even-numbered days and Wingaersheek on odd ones at the time of writing. A cough can follow a weekend of beach play as easily as it follows a daycare day.

A vet usually diagnoses kennel cough from the history and the sound. Merck explains that the diagnosis rests on recent contact with other dogs and the clinical signs, that chest X-rays help judge severity and rule out other causes, and that swabs from the nose or throat can be sent for PCR testing to name the germ. MSPCA-Angell calls PCR the most practical test for the viruses involved. Your vet decides whether any testing is needed and what care, if any, fits your dog.

Some signs mean the infection may have reached the lungs. Cornell lists labored breathing, a moist cough, high fever and nasal discharge as signs of pneumonia, and MSPCA-Angell says fever, lethargy, poor appetite and labored breathing appear mostly in puppies, unvaccinated dogs and dogs with weak immune systems. If your dog is struggling for breath, has pale or bluish gums or collapses, go to the nearest emergency hospital; in Woburn, Massachusetts Veterinary Referral Hospital is open around the clock.