Issue Description Infectious canine hepatitis is an acute liver
infection in dogs caused by canine adenovirus type-1 (CAV-1). CAV-1
also causes disease in wolves, coyotes, and bears, and encephalitis in
foxes. The virus is spread in the feces, urine, blood, saliva, and
nasal discharge of infected dogs. It is contracted through the mouth
or nose, where it replicates in the tonsils. The virus then infects
the liver and kidneys. The incubation period is 4 to 7 days.
Symptoms Symptoms include fever, depression, loss of
appetite, coughing, and a tender abdomen. Corneal edema and signs of
liver disease, such as jaundice, vomiting, and hepatic encephalopathy,
may also occur. Severe cases will develop bleeding disorders, which
can cause hematomas to form in the mouth. Death can occur secondary to
this or the liver disease. However, most dogs recover after a brief
illness, although chronic corneal edema and kidney lesions may
Diagnosis is made by recognizing the combination of symptoms and
abnormal blood tests that occur in infectious canine hepatitis. A
rising antibody titer to CAV-1 is also seen. The disease can be
confused with canine parvovirus because both will cause a low white
blood cell count and bloody diarrhea in young, unvaccinated dogs.
Treatment Most dogs recover spontaneously without
treatment. Prevention is through vaccination. Most combination
vaccines for dogs contain a modified canine adenovirus type-2. CAV-2
is one of the causes of respiratory infections in dogs, but it is
similar enough to CAV-1 that vaccine for one creates immunity for
both. CAV-2 vaccine is much less likely to cause side effects than
CAV-1 vaccine. One study has shown the vaccine to have a duration of
immunity of at least four years.
CAV-1 is destroyed in the
environment by steam cleaning and quaternary ammonium compounds.
Otherwise, the virus can survive in the environment for months in the
right conditions. It can also be released in the urine of a recovered
dog for up to a year.