Current concepts in the treatment of canine chronic hepatitis.

Chronic hepatitis is a common disorder in dogs seen by general practitioners. Several new drugs have been marketed for treating this disease. Unfortunately, there are few controlled studies that examine the efficacy of these medications for the treatment of canine chronic hepatitis. A rational therapeutic approach can be implemented based on histopathologic findings of a liver biopsy. A liver biopsy is essential for establishing a definitive diagnosis and guiding the optimal therapy. The biopsy allows characterizing the inflammatory process, quantitating hepatic copper concentrations, and determining if fibrosis is present. Copper associated hepatopathy is treated with zinc and copper chelators. Idiopathic chronic hepatitis is thought to be immune mediated. The treatment of idiopathic chronic hepatitis consists of controlling inflammation (prednisone, azathioprine), reversing fibrosis (colchicine), and protecting against oxidant damage (vitamin E, ursodeoxycholic acid, S-adenosylmethionine). The prognosis for chronic hepatitis is quite variable. Dogs with end-stage disease have a poor prognosis, while dogs diagnosed earlier can have a mean survival of years. Early diagnosis and intervention are key to the successful treatment of dogs with chronic hepatitis.