In this study, an attempt was made to evaluate two models of chemically induced fulminant hepatic failure (FHF) in pigs: acetaminophen (Ac); and d D-galactosamine (dGal). In Model I, five animals were pretreated with buthionine sulfoximine before dosing them with Ac over a 12 hr period. In Model 2, six animals received a single dose of dGal. The animals were followed clinically and biochemically with serial prothrombin time (PT), serum ammonia (NH3) and transaminase levels (TA) for evidence of liver failure. Pigs given a single dose of dGal formed an excellent model of FHF.