Medical records of 151 dogs with chronic hepatitis were reviewed. Corticosteroid treatment had a statistically significant (P less than 0.005) effect on improving survival time when corticosteroid-treated dogs were compared with untreated dogs. Dogs dying within 1 week of examination represented 37.1% of the cases, and when compared with those living more than 1 week, serum glucose concentration was significantly lower (P less than 0.001); prothrombin time and partial thromboplastin time were significantly longer (P less than 0.001); blood ammonia concentration after oral administration of ammonium chloride was significantly higher (P less than 0.05); and necrosis severity and fibrosis severity were significantly greater (P less than 0.05 and P less than 0.022, respectively). The best predictors of early death were low normal serum glucose concentration (P less than 0.001) and prolonged prothrombin time (P less than 0.030), which was abnormal in 60.0% of dogs dying early. Partial thromboplastin time, which was increased in 92.0% of dogs dying early and in 42.6% of dogs living more than 1 week, was a less reliable predictor. Plasma ammonia concentration after oral administration of NH4Cl was least reliable in predicting early death. In dogs living more than 1 week, hypoalbuminemia was a predictor of shorter survival time (P less than 0.003). Of all the histologic features evaluated, only necrosis severity and fibrosis severity were accurate predictors of early death. The presence of bridging fibrosis was a predictor of shorter survival time in dogs living more than 1 week (P less than 0.0002).