Anthelmintic efficacy of comercial formulations in horses from Douradina municipality, Paraná

Abstract

The aim of this study was to evaluate the efficacy of commercial anthelmintics in horses. From three farms in the Douradina, PR, municipality, it was selected a total of 51 cross-breed horses, male and female, from different ages, naturally infected by gastrointestinal nematodes and submitted to treatment with (I) oral solution of closantel (10mg/kg), (II) paste containing oxifendazole (2.5mg/kg) + triclorfon (40mg/kg) or (III) gel containing ivermectin (200mcg/kg) + praziquantel (2,5mg/kg) + vitamin E (1mg/kg). Due to the limited number of available horses on farm B, it was used only treatments II and III and only treatment III on farm C. EPG counts and coprocultures were done before and seven days after the treatment.  Closantel showed 68.78% efficacy while treatment II showed efficacy of 72.74% and 92.11% on the two evaluated farms. Treatment III showed 100% efficacy on the three farms. The coprocultures indicated that the treatment surviving nematode belonged to the Cyathostominae sub-family. It was demonstrated the absence of resistance to ivermectin and the reduced efficacy of closantel and the association of oxifendazole  + triclorfon, against cyathostomes, which are the most common nematode in horses in Brazil.