Veterinary Science & Technology

Safety Assessment of Etofenprox, S-Methoprene, and Piperonyl Butoxide in Dogs Topically Exposed to Bio Spot Defense

Abstract

Stephanie D Bland, Ramesh C Gupta, Michelle A Lasher and Terry D Canerdy

Use of ectoparasiticides on pets seems inevitable since pets are commonly infested with fleas, ticks, and many other external parasites. Currently, pyrethroids are more commonly used than any other class of ectoparasiticides because they are considered relatively safe. Due to paucity of data, serious concerns have been raised not only about their safety in dogs but their transferable residues to owners, veterinarians, veterinary technologists, and dog handlers who come in contact with treated dogs on a daily basis. The present investigation was therefore undertaken to determine the toxicity and safety of “Bio Spot Defense” applied to six adult dogs, and to determine the residue of active ingredients (etofenprox, s-methoprene, and piperonyl butoxide) in blood of dogs and cotton gloves worn for five minutes to pet dogs at 24, 48, 72 hours, and 1, 2, 3, 4, and 5 weeks post-application. At these time intervals, dogs were evaluated for physical examination. Residues of active ingredients were confirmed and quantitated using GC/ MS. In the blood, etofenprox was detected as early as 48 hours (18.42 ± 5.05 ìg/g) and the residue persisted until 1 week (0.80 ± 0.35 ìg/g). S-methoprene and piperonyl butoxide were not detected in the blood. In the gloves, the highest concentrations of etofenprox, s-methoprene, and piperonyl butoxide were determined at 24 hours (9,552.00 ± 1551.83; 2,307.86 ± 456.70; and 1286.13 ± 0.49 ìg/g, respectively). Residues of all three compounds were detected in appreciable concentrations in the gloves until 1 week (294.86 ± 27.22; 80.62 ± 10.06; and 40.49 ± 5.78 ìg/g, correspondingly). Their residues persisted in insignificant amounts in gloves until 5 weeks. In conclusion, findings of this investigation suggest that Bio Spot Defense product appears to be safe for dogs and their owners, but the veterinary personnel can be exposed to significant levels of etofenprox, s-methoprene, and piperonyl butoxide following chronic exposure, if not properly protected.