Infectious Hepatitis (Adenovirus) in Dogs

By Malcolm Weir, DVM, MSc, MPH; Tammy Hunter, DVM; Ernest Ward, DVM

What is hepatitis?

Hepatitis is defined as inflammation of the liver. As a specific disease, infectious canine hepatitis (ICH) is a viral infection caused by a member of the adenovirus family. Other members of the dog family (e.g., foxes), as well as otters and bears, can be infected, but the ICH virus is harmless to people.

"...infectious canine hepatitis (ICH) is a viral infection caused by a member of the adenovirus family."

How is the canine hepatitis virus spread?

The hepatitis virus is present in the urine and in the nose and eye discharges of infected animals. The virus is transmitted by direct contact with these infected materials. Young dogs are at the highest risk of contracting this virus and signs of disease usually occur within two to five days after exposure. However, the incubation period (time before clinical signs appear) can be as long as 14 days. In older dogs, some ICH infections may go unnoticed or be mild and resolve without medical intervention.

What are the clinical signs?

In the mild form, an affected dog may merely have a decreased appetite, appear depressed, and have a mild fever. Some dogs develop opacity (cloudiness) of one or both corneas of their eyes (so-called blue eye) one to two weeks later. Dogs may have respiratory signs, such as eye and nasal discharge and a cough that is indistinguishable from other forms of upper respiratory tract infections or kennel cough (see handout “Kennel Cough or Tracheobronchitis in Dogs”).

In severe cases, usually in young puppies, along with the fever, depression, and loss of appetite, there is abdominal pain, vomiting, diarrhea, edema (fluid swelling under the skin) of the head and neck, and possibly jaundice. Such cases are often fatal.

What is the treatment?

As with most viral infections, there is no specific treatment. Antibiotics are ineffective against viruses but may help to treat secondary bacterial infections. Treatment is aimed at reducing symptoms and giving time for the dog's immune system to respond. This includes hospitalization, intravenous fluids, and medications to reduce the severe symptoms.

Is there a vaccine that can help protect my dog?

"The ICH vaccine is routinely administered in puppy vaccination programs."

Vaccination has been very successful at reducing the prevalence of this disease. The ICH vaccine is routinely administered in puppy vaccination programs. Protection lasts for many months but it does decrease with time. Once your dog reaches adulthood, your veterinarian will discuss the appropriate vaccination schedule for your dog, including the need for booster revaccination. After the first annual booster, the American Animal Hospital Association (AAHA) recommends vaccinating all dogs every three years against ICH with an approved vaccine.

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