Symptoms of kennel cough in dogs include a loud cough and possibly fever, a runny nose and white, foamy phlegm, according to WebMD and the ASPCA. The cough, typically the most noticeable symptom, sounds like a forceful honk and may cause people to think mistakenly that a dog is choking.
Dogs with kennel cough may also sneeze or have eye discharge, but WebMD and the ASPCA agree that they usually appear healthy otherwise, with little or no change in appetite or energy level. Symptoms may worsen during or after exercise or if a dog wears a neck collar and tends to pull against his leash. Bacterial and viral sources combine to create kennel cough, which is technically a form of bronchitis and resembles a chest cold in humans. Though the condition may clear up on its own, it is quite contagious and spreads easily through even casual contact between dogs, so an owner should isolate an infected pet. Animal health professionals recommend that a veterinarian examine a coughing pet so that the doctor can try to determine the cause of the cough and prescribe a treatment, such as antibiotics, if necessary. Kennel cough may persist in puppies, older dogs and dogs with compromised immune systems, or may develop into a more serious illness such as pneumonia, so a vet visit becomes more important for these dogs.