Hepatic Encephalopathy: Warning Signs Checklist

Anatomic arrangement of the liver lobes and extrahepatic biliary tract. A, Diaphragmatic aspect of the liver. B, Visceral aspect of the liver. C, Liver lobes, gallbladder, and hepatic ducts, visceral aspect. (From Evans HE: The digestive apparatus and abdomen. In Evans HE, de Lahunta A: Miller’s anatomy of the dog, ed 4, St Louis, 2013, Saunders/Elsevier.)

Hepatic encephalopathy (HE) is a brain disturbance caused by liver dysfunction. When the liver can no longer clear toxins such as ammonia from the blood, they build up and affect the brain. The important thing for owners to understand is that HE often comes in episodes — your dog or cat may seem completely normal in between, and signs are frequently worse after a high-protein meal. That is exactly why the early warning signs are so easy to miss.