Infectious canine hepatitis

• Canine adenovirus A
• Canine adenovirus
• Canine adenovirus 1 (CAV-1)
• Canine adenovirus 2 (CAV-2)

Infectious canine hepatitis (ICH) is an acute liver infection in dogs caused by Canine adenovirus 1 (CAV-1). Canine mastadenovirus A 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 9 days.

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.

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 is symptomatic. Most dogs recover spontaneously without treatment. Prevention is through vaccination (ATCvet code and various combination vaccines). 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.

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.