FURTHER-STUDIES ON ALLOPURINOL-INDUCED HYPERURICEMIA AND VISCERAL GOUT IN RED-TAILED HAWKS (BUTEO-JAMAICENSIS)

To investigate the usefulness of allopurinol for the treatment of hype ruricemia in birds, experimental studies were performed using the phys iologically occurring post-prandial hyperuricaemia in birds of prey as a model. pre-and post-prandial plasma concentrations of allopurinol, oxypurinol, xanthine, hypoxanthine and uric acid were established by h igh performance liquid chromatography in red-tailed hawks (RTM, Buteo jamaicensis) at various time intervals after receiving allopurinol (50 mg/kg SID) or placebo. The dosage used caused slight, but significant ly elevated plasma uric acid concentrations compared to controls, as w ell as vomiting in the majority of treated birds. Markedly elevated pl asma concentrations of oxypurinol, xanthine and hypoxanthine were seen in experimental birds. Toxic signs were attributed to oxypurinol, the active land toxic) metabolite of allopurinol. Xanthinuria was conside red to be the cause of the observed renal function disorder, Extrapola tion of data from studies in humans and combining these with those of the present study suggest that the maximum dose of allopurinol that ca n be safely administered to]RTH is about half the dose given in the pr esent study, but this needs verification.