INFECTIOUS CANINE HEPATITIS) (ICH)

1. INFECTIOUS CANINE HEPATITIS) (ICH)

2. Infectious canine hepatitis is a worldwide, contagious disease of dogs with signs that vary from a slight fever and congestion of the mucous membranes to severe depression, severe reduction in white blood cells, and deficiency of blood clotting. • In recent years, the disease has become uncommon in areas where routine vaccination is used.

3. Etiology and Pathogenesis • ICH is caused by a DNA virus, canine adenovirus 1(CAV-1), which is antigenically related only to CAV-2 (one of the causes of infectious canine tracheobronchitis (kennel cough) • Consumption of urine, feces, or saliva from infected dogs is the most common route of infection. • Recovered dogs shed virus in their urine for at least 6 months. The virus targets the liver, kidneys, spleen, and lungs, though other organs are occasionally involved. • Long-term kidney damage and clouding of the cornea of the eye (“blue eye”) result from immune-complex reactions after recovery from the disease.

4. Clinical Findings • Signs vary from a slight fever to death. • The mortality rate is highest in very young dogs. • The first sign is a fever higher than 104°F (40°C), which lasts 1 to 6 days and usually occurs in 2 stages. If the fever is of short duration,a low white blood cell count may be the only other sign. If the fever lasts for more than 1 day, other signs of illness, such as an increased heart rate, develop. • On the day after the initial temperature rise, the white blood cell count drops and stays low throughout the feverish period. • The severity of the fever seems to relate to the severity of the infection.

5. Other signs of infection include apathy, loss of appetite, thirst, inflammation of the eyes, and a watery discharge from the eyes and nose. • Occasionally there may be abdominal pain and vomiting. • The nose and mouth may be reddened or covered with small bruises. • Enlarged tonsils and swelling of the head, neck, and trunk may occur. • It may be difficult to get an infected dog’s blood to clot. • Respiratory signs may be seen in a few dogs with infectious canine hepatitis

6. Although central nervous system involvement is unusual, severely infected dogs may develop convulsions from brain damage. • Slight paralysis, caused by bleeding in the brain, may also occur. • After recovery, dogs eat well but regain weight slowly.

7. Diagnosis • Usually, the abrupt onset and bleeding suggest a diagnosis of infectious canine hepatitis, but laboratory tests are needed for confirmation. • Postmortem gross changes in the liver and gall bladder are more conclusive and diagnosis is confirmed by virus isolation, immunofluorescence, • characteristic intranuclear inclusion bodies in the liver.

8. Treatment • Treatment is symptomatic and supportive • The purpose is limit secondary bacterial invasion, support fluid balance, and control hemorrhagic tendencies • Because of blood loss, Plasma or whole • blood transfusions may be necessary to treat • severely ill dogs. • In addition, intravenous electrolyte • solutions With 5% dextrose supplementation • are indicated. • The veterinarian will likely recommend • treatment with a broad--spectrum antibiotic.

9. Although the clouding of the • Cornea of the eye • (transient corneal opacity) • usually requires no treatment, • an eye Ointment to alleviate the • painful spasm that is sometimes • associated with it. • Dogs with corneal clouding • should be protected against bright light. • Systemic corticosteroids are contraindicated for the treatment of corneal opacity associated with ICH

10. Prevention • Modified live virus vaccine (MLV) injectable vaccines are available and often combined with other vaccines. • Vaccination against ICH is recommended at the time of Canine distemper vaccinations. • Maternal antibody from immune bitches interferes with active immunization in puppies until they are 9-12 weeks old. • Annual revaccination against infectious canine hepatitis is often recommended.