Infectious Canine Hepatitis
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This article is still under construction. |
| Also known as: | Rubarth's Disease Canine adenovirus infection |
Description
Infectious Canine Hepatitis (ICH) is a highly contagious disease of dogs caused by Canine Adenovirus 1 (CAV1). This virus is closely related to Canine Adenovirus 2, which causes respiratory disease.
Canine Adenovirus 1 may be shed in the urine for up to nine months following an active infection, and is also spread by infected faeces and fomites. After invasion via the oronasal route, CAV1 infects and replicates in the cells of the oropharynx. A viraemia becomes established, which allows dissemination of infection to other tissues. CAV1 has a tropism for hepatic parenchyma and vascular endothelium, and so the key target organs are the liver, vascular endothelium, kidney and eye.
Signalment
- young dogs
Diagnosis
Clinical Signs
- recovering animals may show an immune-mediated uveitis with corneal opacity
Laboratory Tests
Radiography
Biopsy
Endoscopy
Pathology
Gross
The liver is enlarged and friable on post-mortem examination. Extensive centrilobular necrosis leads to a pale, mottled appearance, but widespread haemorrhage is also apparent. These haemorrhages are located particularly on the serosal surface. Ascites results from this hepatitis, and fibrinous or fibrino-haemorrhagic adhesions can sometimes be seen between the lobes of the liver.
Other organs may also show changes. For example, the wall of the gall bladder may be oedematous, and lymph nodes can be enlarged, reddened and haemorrhagic. Chronic interstitial nephritis may feature.
Histological
Histopathology reveals centrilobular necrosis. Haematoxylin and eosin staining reveals basophilic intranuclear inclusion bodies in hepatocytes and macrophages. It is possible to use immunofluorescence to stain for viral antigen in vascular endothelium.
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