Comparative pharmacokinetics of febantel and its metabolites in sheep and cattle.

The pharmacokinetics of febantel and its main metabolites were studied in cattle and sheep. Seven ewes and 4 heifers were given febantel orally in a single dose of 7.5 mg/kg, 25 mg/kg, or 45 mg/kg of body weight. Plasma concentrations vs time of febantel and individual metabolites were determined by high-performance liquid chromatography analysis. Intestinal absorption of febantel was faster and biotransformations were more active in sheep than in cattle.