The primary goals of therapy of HE are to identify and correct any precipitating factors, reduce the number of toxin-producing bacteria in the intestinal tract, decrease absorption of the intestinal toxins, and promptly recognize and treat any complications of liver dysfunction. Once therapy is initiated, most animals have a dramatic alleviation of the signs of HE. Remove predisposing cause. There are many factors that can precipitate an episode of HE. Many drugs that require metabolism by the liver can adversely affect the nervous system in animals with liver disorders, most notably anesthetics and sedatives. These drugs should be avoided. Gastrointestinal bleeding can precipitate HE, so potentially ulcer-causing drugs such as aspirin should be discontinued, and gastrointestinal parasites that might cause intestinal bleeding, such as hookworms, should be addressed. Infections can predispose animals to HE, and must be treated promptly.
Antibiotics. Bacteria in the intestinal tract generate ammonia and other toxins that precipitate HE. The primary means of decreasing the number of these detrimental bacteria is with antibiotics. Neomycin, ampicillin and metronidazole are examples antibiotics commonly prescribed to reduce the number of detrimental bacteria in the intestinal tract.
Lactulose. Lactulose is a synthetic sugar. When given orally, it acidifies the contents of the colon. This traps ammonia and other toxins in the colon and prevents it from being absorbed into the bloodstream. These toxins are excreted into the feces instead. Lactulose and antibiotics are best used in combination in patients with moderate-to-severe HE (grades 2, 3 or 4), or if either drug alone fails to eliminate clinical signs.
Diet. Although antibiotic and lactulose therapy is critical in the acute management of HE, dietary therapy has long been considered the backbone of long-term therapy. Animals with liver disease and HE need to have their diet modified, most notably in terms of protein content. A major dilemma in formulating diets for animals with liver disease is the fact that these animals are usually stunted or malnourished, and it is vitally important to maintain body weight and muscle mass while minimizing the signs of HE. Fortunately, there are prescription diets that are designed to provide reduced levels of high quality protein, including a new diet from the Hill's company specifically designed for animals with liver disease (Hill's Science Diet Prescription Diet L/D).
Surgery. For portosystemic shunts, surgery can significantly improve your cat's health. Unfortunately, surgery is not possible for certain types of shunts. Those shunts that are small and occur outside of the liver are the best candidates for surgery. Multiple shunts within the liver are rarely surgical candidates.