Hepatic Encephalopathy Associated with Acquired Portosystemic Shunts in a Dog.

An 8-month-old dog with a history of gastrointestinal disturbances and neurological signs was presented with hyperammonemia. Necropsy revealed ascites, portosystemic collaterals, and an irregularly surfaced small liver. Histologically, there were diffuse neuronal necrosis and focal spongiform changes in the brain, and marked fibrosis in the liver. Hepatic encephalopathy was diagnosed.