However, Ask Dr Mike is available only to subscribers of our Vetinfo Digest. Please do not send questions if you are not a subscriber. Please use the search engine or one of the indexes to see if the information you need is already online. Please see Subscriber info for details. She can't control her head moments very well to drink or eat properly.
Hepatic encephalopathy is central nervous system illness caused by severe liver disease.
To the best of my knowledge, liver failure is the only cause of increased ammonia levels in the bloodstream other than ingestion of ammonia containing products. The ammonia and other toxins not being processed by the liver cause the central nervous system problems. Many neurologic signs are possible, including seizures, tremors, head pressing, blindness, behavioral changes and coma. Lactulose helps because it causes ammonia to be converted to ammonium ions which are not reaborbed into the body like ammonia is. Neomycin kills ammonia producing bacteria, lessening the amount of ammonia exposure.