Infectious canine hepatitis is a highly contagious viral disease caused by canine adenovirus-1. In the United States the disease is rare and is seen almost exclusively in wild canids and unvaccinated dogs. Most cases occur in puppies under 1 year of age.
Following exposure, the virus multiplies in the dog’s tissues and is shed in all body secretions. During this stage, the dog is highly contagious and can spread infection to other dogs who make contact with his infected urine, stool, and saliva. After he has recovered, the dog remains infective and sheds the virus in the urine for up to nine months.
Infectious canine hepatitis affects the liver, kidneys, and lining of the blood vessels, producing a mild infection at one extreme to a rapidly fatal infection at the other. A dog with a mild or subclinical infection loses his appetite and simply appears lethargic. In the fatal form, the dog suddenly becomes ill, develops bloody diarrhea, collapses, and dies within hours. Puppies may die without obvious illness.
A dog with acute infection runs a fever up to 106°F (41.1°C), refuses to eat, passes bloody diarrhea, and, often, vomits blood. The dog has a tucked-up belly caused by painful swelling of the liver. Light is painful to the dog’s eyes and causes tearing and squinting. Tonsillitis, spontaneous bleeding beneath the gums and under the skin, and jaundice may occur.
Infectious hepatitis can be suspected by the signs and symptoms and confirmed by virus isolation tests. About 25 percent of dogs recovering from infectious canine hepatitis develop a characteristic clouding of the cornea of one or both eyes known as blue eye. In most cases blue eye disappears within a few days.
Treatment: Acute cases must be hospitalized for intensive veterinary treatment.
Prevention: Vaccination is highly effective in preventing infectious canine hepatitis. Infectious canine hepatitis does not cause hepatitis in humans.