Primarily it affects the liver, kidneys and lining of the blood vessels. Infectious canine hepatitis presents a variety of signs and symptoms that range from those of a mild infection to one of an extreme and rapidly fatal infection. At times it is difficult to distinguish from distemper. A few days after a dog is exposed, the virus multiplies in the dogs tissues and is shed through its stool, saliva and urine which is extremely infectious to other dogs. Convalescing dogs or those that have recovered may shed the virus through their urine for several months.
Puppies are especially at risk although dogs of all ages are susceptible.
In the fatal form affected dogs can suddenly become ill developing bloody diarrhea, collapsing and dying. In mild cases the dog simply appears lethargic or below normal health and shows a lack of appetite. In acute cases the dog may run a fever reaching 106 degrees F. the dog passes bloody diarrhea, may vomit blood and will refuse to eat. The eyes may be sensitive to light causing squinting. The distemper can live for many years in a frozen state.