Plasma concentrations of enrofloxacin in African grey parrots treated with medicated water

Plasma concentrations of enrofloxacin were measured four times during a 7-day treatment period in African grey parrots that were fed with enrofloxacin-medicated drinking water. Water medicated at doubling doses of 0.09, 0.19, 0.38, 0.75, 1.5, and 3.0 mg/ml achieved mean concentrations (+/- SEM) of 0.10 (+/- 0.05), 0.12 (+/- 0.05), 0.12 (+/- 0.03), 0.15 (+/- 0.05), 0.30 (+/- 0.11), and 0.20 (+/- 0.06) micrograms/ml, respectively. A portion of the administered enrofloxacin was metabolized to an equipotent metabolite, ciprofloxacin. Mean ciprofloxacin concentrations paralleled enrofloxacin concentrations but were lower, ranging from 0.04 to 0.27 micrograms/ml. Acceptance of medicated water was adequate at lower doses; however, at doses of 1.5 and 3.0 mg/ml, acceptance was unsatisfactory, and mean weight loss in these groups was significantly higher than the control group. Based on the concentrations achieved in these preliminary trials and the susceptibility patterns of gram-negative bacteria isolated from psittacine birds, drinking water medicated with enrofloxacin at 0.19-0.75 mg/ml might be effective for treating highly susceptible gram-negative bacterial infections in African grey parrots.