In vivo effect of cypermethrin on horses infested by Anocentor nitens: clinical and hematological acute evaluation

Abstract

The Anocentor nitens is specie of the tick found in the whole of America infesting horses and other equines, having an important role in pathogenic microorganism dissemination. The pyrethroids are used for these arthropod control, and could be classified into two groups: those which do not have α-ciane group, used commonly as insecticides in home environments, while those which have α-ciane, in case the cypermethrin, the deltamethrin, the cyfenothrin, the fenvalerate, the flumethrin and the cyalothrin, that are designated as ectoparasiticides for animal use. The goal of this study was to evaluate the in vivo effect of cypermethrin on clinical and hematological acute parameters in horses. To this end, clinically healthy animals were used, in number 15 horses, although infested by ticks of revered species. The animals which were submitted to clinical examination, ticks counting and blood samples collection, aiming to make a laboratorial and divided into three moments as follow: zero, before cypermethrin treatment and 24 and 48 hours after treatment. Except for aspartate aminotransferase (AST) elevated since experiment beginning, the others hematological values evaluated were kept on species standard, did not showing statistical difference among moments evaluated (P>0.05). In conclusion, the cypermethrin at 15% on dilution rate used did not induce clinical or hematological acute alterations in horses.