Hepatitis, a disease of the liver that is seen in several animals, including humans, is caused by a viral infection. Canine hepatitis is caused by the virus designated CAV-1 which is seen only in dogs. Humans and other animals are not at risk to contract hepatitis from the CAV-1 virus.

The canine distemper virus (CDV) causes a highly contagious disease in dogs known as distemper. Dogs who contract distemper suffer damage to their gastrointestinal, central nervous and respiratory systems. Distemper is incurable and often fatal.