Effects of a Single Intramuscular Dose of Rasburicase on Plasma Uric Acid Concentrations in Fasted and Fed Ball Pythons (Python regius)

Background: Hyperuricemia is a common problem in captive reptiles and is associated with gout and renal disease. Rasburicase is a recombinant urate oxidase that converts uric acid into allantoin, a more water-soluble metabolite. This study evaluated the safety and efficacy of rasburicase in clinically healthy ball pythons (Python regius). Methods: Eight adult ball pythons were included in a prospective crossover study. Six experimental conditions were evaluated: fasting with and without rasburicase (0.2 mg/kg IM), feeding with a day-old chick with and without rasburicase, and feeding with a mouse with and without rasburicase. Plasma uric acid concentrations were measured at 0, 24, 48, 72, and 96 h. Results: Rasburicase did not significantly affect fasting uric acid concentrations. Feeding increased plasma uric acid concentrations, with peak values occurring between 24 and 72 h. Following chick consumption, rasburicase promoted a faster decline in UA concentrations, although differences were not significant (p = 0.907). Following mouse consumption, rasburicase significantly reduced UA concentrations (p = 0.002), with a mean reduction of 37.85%. No changes were observed in behavior, appetite or defecation. Conclusions: Rasburicase was well tolerated and reduced postprandial uric acid concentrations in ball pythons.