Canine distemper is a contagious and serious disease caused by a virus that attacks the respiratory, gastrointestinal and nervous systems of puppies and dogs.
Initially, infected dogs will develop watery to pus-like discharge from their eyes. They then develop fever, nasal discharge, coughing, lethargy, reduced appetite, and vomiting. As the virus attacks the nervous system, infected dogs develop circling behavior, head tilt, muscle twitches, convulsions with jaw chewing movements and salivation (“chewing gum fits”), seizures, and partial or complete paralysis. The virus may also cause the footpads to thicken and harden, leading to its nickname “hard pad disease.”