What causes Hepatitis in Dogs

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Dog laying down with bone
Dog Laying Down With Bone

Although Hepatitis in dogs is contagious and can be found worldwide, it's uncommon in areas where dogs are routinely vaccinated. Its severity ranges widely from very mild cases to very serious and sometimes fatal disease.


Infectious canine hepatitis is caused by a virus called canine adenovirus type 1 (CAV-1).

Risk Factors

Young dogs and unvaccinated dogs are at the highest risk of being infected with the virus causing infectious canine hepatitis. Very young puppies tend to develop the most serious illness.

Signs and Symptoms

Infectious canine hepatitis can cause a range of symptoms. Some dogs show very mild symptoms, but in severe cases, the disease can be fatal. Symptoms can include any of the following:

adult brown bull dog riding a skateboard
adult brown bull dog riding a skateboard
black and white short coated dog on green grass during daytime
black and white short coated dog on green grass during daytime
short-coated brown dog
short-coated brown dog
  • Fever
  • Loss of appetite
  • Lethargy
  • Runny eyes and nose
  • Cough
  • Vomiting
  • Bleeding which may present as bruising, a skin rash, nose bleeds, or blood in the urine or feces.
  • Swelling of the head, neck, and trunk
  • Fluid accumulation in the abdomen (ascites)
  • Jaundice (yellowish tinge to skin)
  • Seizures, walking in circles, pressing of the head against the wall, or other neurologic symptoms.
  • Increases thirst and urination (secondary to kidney damage)
  • Bluish clouding of the cornea (hepatitis blue-eye)


Various methods are available to test for the presence of the virus causing infectious canine hepatitis, or the presence of antibodies to the virus. Blood tests can be suggestive of the diagnosis when combined with the clinical signs, depending on the stages of the disease. A decrease in white blood cells and evidence of liver disease may be evident relatively early in the disease. Other tests such as radiographs and urine tests may also be performed.


There is no specific treatment for infectious canine hepatitis, so treatment is aimed at managing the symptoms until the virus runs its course. Depending on the severity of illness, hospitalization and intravenous fluid therapy may be necessary. Antibiotics don't treat the virus but may be prescribed to ward off secondary bacterial infections. In severe cases, blood transfusions may be necessary.


Vaccines are available to prevent infectious canine hepatitis and are among the core vaccines recommended for all dogs (the combination vaccines often used for dogs protect against infectious canine hepatitis). Vaccination against a closely related virus, canine adenovirus type 2 (CAV-2 protects against both infectious canine hepatitis (CAV-1) and respiratory illness caused by CAV-2. CAV-2 vaccines are most commonly used to protect against both of these viruses due to the potential for side effects from the CAV-1 vaccine. Your vet will recommend a series of vaccines appropriate for your dog to protect against this and other common canine diseases.