LAUSR

Abstract: Ponazuril, a novel coccidiocidal triazinetrione, has shown promise in addressing apicomplexan diseases in mammals and birds. This study describes the pharmacokinetics of ponazuril in healthy adult Indian peafowl (Pavo cristatus) following a single oral dose administered at two different dosages. Peafowl (four males and four females) were administered compounded ponazuril at 20 or 40 mg/kg orally in a double crossover design, with a 2-wk washout period. Blood was collected from each bird at 2, 4, 8, 24, 48, 72, 96, and 120 h after administration for plasma concentration of ponazuril using high-pressure liquid chromatography. Fecals were evaluated for coccidial shedding for 3 consecutive d prior to the ponazuril trial, 1 wk after the first dose of ponazuril, and 1 wk after the second dose of the trial. After the first trial, one peafowl administered 20 mg/kg ponazuril was shedding coccidia, but no coccidia were detected by the end of the second trial. Ponazuril reached peak concentrations (Tmax) at 21.38 h + 5.25 and 22.04 h + 7.39, and peak concentration (Cmax) were 11.82 µg/ml + 3.01 and 18.42 µg/ml + 4.13, for 20 and 40 mg/kg doses, respectively. Ponazuril was detected at 120 h with a concentration of 9.48 µg/ml + 2.59 and 12.25 µg/ml + 2.89 and a half-life of 219.4 + 58.7 h and 186.7 + 58.7 h, for and 40 mg/kg doses, respectively. Ponazuril in peafowl was well absorbed orally, plasma concentrations increased with dose, and elimination was slower than current dosages for birds would suggest. No obvious adverse effects were observed at either dosage.