Pharmacokinetics and potential use of gentamicin in budgerigars (Melopsittacus undulatus)

The pharmacokinetics of gentamicin were evaluated in budgerigars. Intramuscular (i.m.) administration of 5 and 10 mg/kg dosages produced serum gentamicin concentrations of 17.3 and 37.0 micrograms/ml respectively, at 0.25 hr following injection, but concentrations declined with a terminal half-life of 0.53 h. Based on these results, a dosage regimen of 5 to 10 mg/kg of gentamicin, intramuscularly, every 8 hours for up to 3 days, was considered to be safe and could be used against many of the common bacterial infections in budgerigars. Serum AST, ALT, LDH, CK, creatinine and uric acid values were determined after i.m. injection of either gentamicin or physiological saline every 8 hours for up to 3 days, and tissue samples of various organs were examined histologically. The most prominent adverse effect found was muscular damage at the injection site. Measurement of AST, ALT and CK activity seemed to be a sensitive method to determine pathological changes at the injection site in the budgerigars.