ASSESSMENT OF THE EFFICACY OF ANTHELMINTICS IN QUARTER HORSE NATURALLY INFECTED EQUINES ON A PROPERTY IN THE NORTHWEST OF PARANÁ

Abstract

This article aimed to evaluate the efficacy of antihelmintics in naturally infected equines. A total of 78 animals of the Quarter Horse breed were selected, comprising different age groups of both males and females, from a property in the municipality of Perobal – PR. The animals were allocated into groups subjected to the following treatments: (T1) fenbendazole (5 mg/kg), (T2) ivermectin (0.2 mg/kg), (T3) moxidectin associated with praziquantel (0.4 mg/kg and 2.5 mg/kg, respectively), (T4) control. OPG counts and coprocultures were performed the day before treatment, as well as seven and fourteen days afterward. The treatment with fenbendazole showed an efficacy of 45%, while ivermectin presented 75%. In contrast, the treatment with moxidectin + praziquantel showed an efficacy of 98.5% in adult animals and 92.8% in young animals after 14 days of treatment. The coprocultures identified a prevalence of 100% of parasites belonging to the subfamily Cyathostominae. It is concluded that after 14 days of treatment, the combination of moxidectin and praziquantel proved effective for treating adult equines; however, concerning the treatment of foals, there was a warning signal regarding efficacy, which could indicate parasitic resistance.