Blood chemistry for the diagnosis of hepatobiliary disease in birds. A review

A review is presented of current knowledge with regard to blood chemistry for the diagnosis of hepatobiliary disease in birds. Straightforward conclusions are difficult, because research on this subject has been limited. Jaundice caused by hyperbilirubinaemia occurs infrequently in birds, because the main bile pigment is biliverdin and not bilirubin. A yellow discolouration of avian plasma is often caused by the presence of carotenoids. The diagnostic value of plasma ALAT concentrations is controversial. Although ASAT and LD are not specific for the liver they appear to be sensitive enzymes to detect liver cell damage. GLDH is liver specific in a number of animal species (including birds) and might prove to be a useful enzyme for diagnostic purposes. AP and GGT seem less useful. Little information is available on the diagnostic value of plasma bile acids and plasma dye clearance tests.