Hepatic Encephalopathy in Cats

Hepatic encephalopathy (HE) is a degenerative disease of the brain caused by severe hepatic insufficiency in advanced liver disease. It is characterized by abnormal mental status, an altered state of consciousness and impaired neurologic function.

The most common cause is a congenital abnormality present at birth called a portosystemic shunt. This is an anatomical defect that causes blood to be diverted around the liver instead of passing through the liver. The liver cannot detoxify the blood and the toxins reach the brain and cause the clinical syndrome. Patients with liver failure due to toxic or infectious causes can also exhibit signs of HE.

There is no age, sex, or breed predisposition for animals with toxic or infectious liver disease; however, animals with congenital portosystemic shunts are usually brought to the veterinarian within the first year of life.