Comparative efficacy of an experimental fasciolicide, triclabendazole and closantel in cattle naturally infected with Fasciola hepatica

Abstract

THE AIM OF THE PRESENT STUDY WAS TO DETERMINE THE EFFICACY OF 5-CHLORO-2-METHYLTHIO-6-(1-NAPHTHYLOXY)-IHBENZIMIDAZOLE CALLED COMPOUND ""ALFA"", WHICH WAS COMPARED WITH TWO COMMERCIAL FASCIOLISCIDES THROUGH THE PERCENTAGE OF F. HEPATICA EGG-REDUCTION IN NATURALLY INFECTED CATTLE. FORTY HOLSTEIN-FRIESIAN ADULT COWS, PREVIOUSLY DETERMINED AS POSITIVE TO FLUKE EGGS BY THE SEDIMENTATION TEST, WERE USED. THEY WERE DIVIDED IN 4 GROUPS (G) OF 10 ANIMALS EACH, AND WERE TREATED WITH THE CORRESPONDING DOSE ON DAY CERO. G1 WAS TREATED WITH COMPOUND ALFA AT 12 MG/KG/PER OS; G2 WITH TRICLABENDAZOLE AT 12 MG/KG/PER OS; G3 WITH CLOSANTEL AT 3.5 MG/KG SUBCUTANEOUSLY, AND G4 REMAINED AS THE NON-TREATED CONTROL. ALL ANIMALS WERE SAMPLED FOR FECES TO CARRY OUT COPROLOGICAL EXAMINATIONS ON DAYS ""15, ""8, 0, 7, 14, 21, 28, 60 AND 90. EFFICACY WAS ASSESSED ON THE REDUCTION OF EGG OUTPUT ON DAYS 14 AND 21 AFTER THE TREATMENT WITH RESPECT TO THE CONTROL GROUP. RESULTS SHOWED AN EFFICACY OF 90.1% AND 85.3% FOR COMPOUND ALFA, 91.5% AND 96.5% FOR TRICLABENDAZOLE AND 82.1% AND 92.1% FOR CLOSANTEL. ADDITIONAL PARAMETERS SUCH AS PERCENTAGE OF PREVALENCE, MEAN NUMBER OF F. HEPATICA EGGS, STANDARD DEVIATION, EXTENSION AND INTENSITY EFFECT WERE ALSO MEASURED. NO STATISTICAL DIFFERENCES WERE FOUND BETWEEN TREATMENTS. IT IS CONCLUDED THAT ALL COMPOUNDS TESTED CONSIDERABLY REDUCED THE PERCENTAGE OF EGG EXCRETION, SHOWING AN ACCEPTABLE FASCIOLICIDE EFFICACY.