Detection of anthelmintic efficiency in nematodes of hair sheep using the faecal egg reduction test

摘要

Formanyyearschemicalproductshavebeenusedtocontrolgastrointestinalparasitesinsheepandtheirusehasoriginatedanthelminticresistance.TheobjectiveofthisstudywastoevaluatethereductionofeggsofnematodesinthreeflocksofhairsheepinthestateofTabasco,Mexicoutilizingdifferentproducts(netobimin,levamisole,ivermectin).ThemethodologyusedwasthatrecommendedbytheWorldAssociationfortheAdvancementofVeterinaryParasitology(WAAVP).Adultpositiveeweswithcountsabove150eggspergramoffaeces(epg)wereused.Groupsfrom10to15positivesheepwereformedandasecondfecalsamplingwasmadeat14dayspost-drenching.TheepgwasobtainedutilizingMcMaster'stechniqueandwormswereidentifiedinthirdstadge(L3).Therewasnoreductionoftheparasiticloadsinthegrouptreatedwithnetobimin(2,128epgpost-drenching)andtheywerehighertothoseofthecontrolgroup(1,158epg).Therewasasignificantreduction(99.6%)inepginagroupofopenandlactatingemptyfemaleswithlevamisole.Therewasnoreductionintheparasiticloadswithivermectin.ThemaingenusfoundintheflockswereHaemonchus,OstertagiaandOesophagostomum.