The activity of certain serum enzymes ornithine carbamyl transferase (OCT), serum isocitric dehydrogenase (SIC-D), total serum lactic dehydrogenase (LDH) and its isoenzymes (LD(1) and LD(5)) was evaluated as a mean of assessing experimental hepatic necrosis on dogs treated with CCl(4). Measurement of activity levels of these enzymes, seldom carried out in veterinary clinical pathology, was made together with tests commonly used in our laboratories: serum glutamic pyruvic transaminase (SGPT), serum glutamic oxalacetic transaminase (SGOT) and serum alkaline phosphatase (SAP), cholesterol, bilirubin and prothrombin time. Measurement of the level of OCT was useful in the diagnosis of liver necrosis. The SIC-D level was important during the first four days of the experiment, but on subsequent days, the enzymatic activity was practically normal. Because of the wide variations of LDH serum levels in normal animals and since many factors influence its activity, the measurement of this enzyme and its isoenzymes was not a good index in the diagnosis of canine liver necrosis. The evaluation of cholesterol and bilirubin was judged of secondary importance because these metabolites are not specific to hepatic problems.A small battery of tests must be used to establish a precise diagnosis and a clear prognosis. To the routine tests like those for SGOT, SGPT and SAP, should be added the evaluation of OCT and SIC-D.