Histomorphological and immunohistochemical studies of chronic active hepatitis in Doberman Pinschers.

Liver tissue samples were reviewed from 35 Doberman Pinschers with chronic active hepatitis in the precirrhotic stage. Thirty dogs had elevated hepatic copper concentrations, and five had normal liver copper concentrations. The earliest changes were inflammation and scar tissue deposition around the small hepatic vein branches. There was also apoptosis of scattered hepatocytes in zone 3. Inflammation consisted of macrophages, lymphocytes, and plasma cells. As the disease progressed, collagen deposition increased around the hepatic veins; in some liver specimens, thin scar tissue septa radiated from the hepatic vein branches, and inflammation spread to include the portal tracts. The sinusoids adjacent to the scar tissue were converted to endothelial-lined, thin-walled vessels. Chronic active hepatitis (commonly referred to as Doberman hepatitis or chronic active hepatitis of Dobermans) is a progressive fibrosis, inflammation and hepatocyte loss beginning among zone 3 hepatocytes around the terminal hepatic vein branches. The histomorphologic changes were the same among those Dobermans with elevated hepatic copper and those with normal hepatic copper. The cause was not determined, but these morphologic studies support the idea of immune-mediated disease.