Comparative efficacy of albendazole, tetramisole and ivermectin against gastrointestinal nematodes in naturally infected sheep in Hawassa, southern Ethiopia

The efficacy of two brands of each of albendazole, tetramisole and ivermectin was tested against gastrointestinal nematodes in naturally infected sheep in Hawassa (southern Ethiopia). One hundred and five male sheep were divided into seven groups of 15 animals the 1(st) group served as the untreated control, the 2(nd) was treated with albendazole1 (ABZ(1)), the 3(rd) with albendazole2 (ABZ(2)), and the 4th with tetramisole I (TTM(1)), 5(th) with tetramisole(2) (TTM(2)). 6(th) with ivermectin 1 (IVM(1)) and 7(th) with ivermectin2 (IVM(2)). Faecal samples were collected on day 0 before treatment, and again on day 12 post-treatment. Efficacy for each anthelmintic was measured using the faecal egg count reduction test (FECRT). The study showed that ABZ(2), TTM(2), IVM(1) and IVM(2). with respective FECRT values of 100%, 99%, 97% and 99% possessed high activity against gastrointestinal nematodes of sheep of the study area. On the other hand ABZ(1). with a 95% FECRT value and TTM(1), also with a 95% FECRT value, had less efficacy against sheep nematodes. Coprocultures from both pre-and post-treatment demonstrated the predominance of Haemonchus spp. A questionnaire survey conducted to gather information on methods of sheep nematode control practices in the study area revealed a lack of basic awareness amongst livestock owners about the best use and efficacy of anthelmintics. In addition, it indicated that farmers within the study area use many practices which may promote the development of anthelmintic resistance. Further detailed studies are necessary to clarify the present anthelmintic resistance status in Ethiopia.