Infectious Canine Hepatitis

Also known as:

Rubarth's Disease Canine adenovirus infection

Description

• adenovirus - Canine Adenovirus 1
• acute and generalised infection
• highly infectious
• spread via the urine of infected animals over a long period of time

Signalment

• young dogs

Diagnosis

• Intranuclear inclusion bodies in hepatocytes can be seen under H&E staining
• Vascular endothelium can be stained for viral antigen by immunofluorescence

Clinical Signs

• recovering animals may show an immune-mediated uveitis with corneal opacity

Pathology

Pathogenesis

• Infects and replicates in the oropharynx
• Viremia as the virus reaches endothelial cells
• Attacks the endothelial lining of gall bladder, liver sinusoids, and Kuppfer cells
• Resulting heptatitis is followed by severe abdominal pain and often death
• Post Mortem: swollen, hemorrhagic liver, ascites, and oedema of the gall bladder
• In older dogs, may present more mildly with lymph node enlargement and chronic interstitial nephritis
• In foxes: virus replicates in the endothelia of the brain resulting in neuronal damage, fits, and paralysis

Gross

• the virus has a tropism for endothelium and hepatocytes
  • widespread haemorrhages, especially on serosal surface
• distinctly pale mottled appearance
  • from extensive necrosis, characteristically periacinar (centrilobular) in distribution - the reason for the increased susceptibility of this area is not known
• enlarged
• friable
• fibrinous or fibrino-haemorrhagic strands between lobes
• gall bladder
  • wall usually shows oedema (up to 2cm diameter)
• lymph nodes and tonsils are enlarged and reddened, sometimes haemorrhagic

Microscopically

• basophilic intranuclear inclusion bodies
  • in hepatocytes and macrophages

Treatment

Control

In an outbreak

• Isolate infected dogs
• Disinfect premises

To prevent

• Vaccination: tissue culture adaptation that may be live or inactivated
• Cross protection with CAV2
• Live vaccines are known to cause keratitis in Afghans, Red Setters and Saluki