Many different serum biochemical tests can help in the diagnosis of liver disturbances in ruminants. The best tests for hepato-cellular damage are the measurement of enzymes such as glutamate dehydrogenase, sorbitol dehydrogenase and, if available, arginase or ornithine carbamoyl transferase. Disturbances of biliary function can be investigated through the measurement of so-called "cholestasis enzyme markers" such as gammaglutamyl transferase or alkaline phosphatases; bilirubin and bile salts can also be helpful. Liver insufficiency can be approached through the measurement of serum albumin, fibrinogen and coagulation tests whereas inflammative and inductive processes are difficult to investigate. Moreover, liver clearances (bromosulfonephtalein or indocyanine green) can provide useful data about whole liver function.