Assessment of liver function in galahs (Eolophus roseicapillus) after partial hepatectomy: A comparison of plasma enzyme concentrations, serum bile acid levels, and galactose clearance tests

The relative sensitivity of conventional assays of liver function was evaluated in comparison with galactose clearance, a test of liver function used in humans since the 1960s. Results of galactose clearance tests were compared with plasma enzyme concentrations and serum bile acid levels in clinically normal galahs (Eolophus roseicapillus; n = 8), after celiotomy (n = 4), and after 6% or 18% hepatectomy (n = 8, respectively). Clearance tests and biochemical analyses were performed within 2-4 hours of surgery and at 4 and 7 days after surgery. Celiotomy and 6% and 18% hepatectomy resulted in changes in alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase concentrations that were consistent with muscle trauma. Celiotomy and 6% hepatectomy did not significantly alter the results of galactose clearance tests; however, 18% hepatectomy resulted in significant reduction in galactose clearance and galactose clearance as a function of body surface area (GEC-SA). Galactose single-point concentrations were not significantly elevated at any time during the experiments; however, single-point concentrations were strongly correlated with galactose clearance and GEC-SA values, especially at 80 minutes after galactose injection. Serum bile acid levels were not significantly elevated after celiotomy or partial hepatectomy. Measurement of galactose single-point concentrations has the potential to be a simple, sensitive method of screening for reduced hepatic function in birds. Galactose clearance and GEC-SA have the potential to be sensitive assays of hepatic functional mass, for use as a noninvasive method of monitoring hepatic function.