Symptoms of Canine Distemper
About half of dogs infected with distemper fight the infection so quickly that they do not appear ill. Some dogs will have a few days of listlessness. The other half of dogs infected with canine distemper develop symptoms. Among those with symptoms, about half will die unless they receive medical care.
Often, the first signs of a canine distemper infection include a runny nose, eye discharge, and fever. These respiratory symptoms typically develop within 24 hours of infection. Dogs with weak immune systems develop pneumonia. Most dogs have no appetite and some vomit and have diarrhea. Because vomiting and diarrhea are typical of parvovirus infection, these symptoms can make it difficult to determine whether a dog has parvovirus or distemper. Respiratory and gastrointestinal symptoms cause dehydration.
Some dogs with canine distemper develop thick, hard paw pads. Dogs infected before their adult teeth are formed develop permanent teeth that are weak and misshapen because the enamel doesn't form. Dogs can have eye problems as the nerves to the eye become inflamed. Almost all dogs experience a drop in the immune system's white blood cells (lymphopenia), and as a result, other infections can invade and make them even sicker.