Regardless of the cause the general signs of liver disease are loss of appetite, depression, and vomiting. More specific signs which may not develop until later in the course of liver disease are jaundice, also called icterus, ( a build up of bile pigments in the blood causing yellow discoloration of areas such as gums and conjunctiva), and ascites (leakage of fluid into the abdomen giving a swollen appearance). Some liver conditions may also cause increased drinking and urinating (polydypsia and polyuria). A syndrome called hepatic encephalopathy may be seen where accumulation of toxins normally filtered by the liver buildup in the brain producing signs including dementia, aggression, seizures and coma.

Laboratory test are generally used to help diagnose liver disease including measurement of the blood levels of a number of enzymes (compounds used in chemical reactions) produced by the liver. Increases in these enzymes can indicate damage to the liver cells or a reduction in the function of the liver. The enzymes include Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Alkaline phosphatase (ALP) and Gamma-glutamyltransferase (GGT). Liver biopsy is the most accurate method of diagnosing many liver conditions and may be important in determining the potential for recovery.

Treatment is generally supportive, based around intravenous fluids (drip) in severe cases and moderation of the diet to reduce the residues needing to be dealt with by the liver. Antibiotics are indicated where infection is suspected. Corticosteroids and chemotherapy may be of use in some progressive liver disorders. There are few liver conditions for which specific treatments are available.