Pharmacokinetic properties of abamectin after oral administration in dogs.

As the introduction of concentrated cattle pour-on products containing abamectin, there have been veterinary reports of both fatal and non-fatal poisoning in New Zealand working dogs. Because these products are highly palatable to dogs, a toxic dose is readily ingested. The pharmacokinetic properties of abamectin in dogs are not published in the public domain. This information is important in understanding the processes of absorption and elimination when treating poisoned dogs and is useful in determining an appropriate treatment for poisoned dogs. The pharmacokinetic properties of abamectin administered orally to six healthy dogs (3 male and 3 female) at a dose of 0.2 mg/kg were established. Plasma concentrations of abamectin were determined by high-performance liquid chromatography (HPLC) coupled with a fluorescence detector. The maximum plasma concentration (Cmax ) for abamectin was 135.52 ± 38.6 ng/ml at 3.16 ± 0.75 h. The elimination half-life (T1/2 elim (h)) was 26.51 ± 6.86 h. The area under the curve (AUC 0-∞) was 3723.50 ± 1213.08 ng h/ml. The mean residence time (MRT) was 38.82 ± 8.93 h. These pharmacokinetic data provide helpful information regarding the treatment of poisoned dogs.