Liver disease can occur in pet psittacine birds of all species and ages. In young birds, infectious causes are most common, whereas in older birds, degenerative diseases are more prevalent. Signs of hepatic disease are dependent on the severity of liver damage. Non-specific signs such as anorexia, listlessness, and fluffed feathering are common. More specific signs include green or yellow colored urates; and polyuria and polydipsia can also occur. Since birds have biliverdin rather than bilirubin, jaundice is rare in avian liver disease. Husbandry concerns may be key to the etiology of hepatic disease, therefore, it is important to obtain a good history. Exposure to other birds, the source of the sick bird, diet, any illness amongst family members, and length of illness are some useful questions to ask. Physical examination may reveal no specific findings of liver disease, although an enlarged liver can be palpated occasionally.

Use signalment and history to limit the rule-out list for hepatic disease. Chlamydial infections can cause liver disease and are more common in younger birds and those exposed to other birds. A longterm pet that never leaves the home is less likely to have psittacosis than a bird just purchased at a bird fair. Other bacteria and viruses such as Pacheco's disease also cause liver dysfunction. Older birds may have degenerative liver ailments such as hepatic lipidosis. Hepatic neoplasia has been described in birds, including reports of biliary adenocarcinoma in blue-front amazons. It is not uncommon for multiple organ disease to be present in association with liver disease in birds. This complicates both diagnosis and treatment.

The ideal initial data base includes a CBC, plasma biochemistries, protein electrophoresis, and bile acids. One or more chlamydial tests may be warranted depending on the signalment. Further tests might include radiographs and coelomic ultrasound. A liver biopsy is often required to determine the etiology.

Treatment of liver disease obviously depends upon the cause. Until an etiology is determined, supportive care is administered. This includes parenteral fluids and tube feedings as most liver disease patients are anorexic. Antibiotics should be given if bacterial hepatitis is suspected. More specific treatments are instituted once etiology is determined.