Lobular dissecting hepatitis in juvenile and young adult dogs.

A specific form of chronic hepatitis is described in 21 dogs. The disease appears to develop in the neonatal and juvenile period. Predominant clinical signs include weight loss, ascites, and jaundice. The liver is small, with a smooth surface or a limited number of hyperplastic nodules. A characteristic feature of the hepatitis is disruption of the hepatic architecture by complete fibrotic dissection of the lobular parenchyma into individual and small groups of hepatocytes with subsequent portal hypertension. This lesion may represent a specific pattern of hepatic reaction in the immature animal, and resembles human neonatal hepatitis.