Detection of Anthelmintic Resistance in Gastrointestinal Nematodes of Small Ruminants in Haramaya University Farms

Abstract

The present study evaluated the status of anthelmintic resistance of gastrointestinal (GI) parasites of small ruminants. The study was conducted from December 2014 to January 2015 in Haramaya University sheep and goat farms. A fecal egg count reduction test (FECRT) was performed in naturally infected sheep and goats. A total of 30 black head Ogaden sheep and 30 Hararghie highland goats of age form 6-18 months not treated in the previous 8 weeks and with a fecal egg counts (FECs) greater than 150 eggs per gram of faeces were selected for the test. Both sheep and goats were grouped into two treatments and one control group (albendazole, ivermectin, and the control). In sheep, the percentage reductions in FECs and the 95% (lower and upper) confidence limit (CL) for albendazole was 82% (95%, CL 60-92), and for ivermectin 68% (95%, CL 0-90). In goats, the percentage reductions in FECs for albendazole was 63% (95%, CL 28-81), and for ivermectin 41% (95%, CL 0-72). The result show that albendazole and ivermectin resistance was detected in nematode parasites of sheep and goats. To overcome the problem, the farm should use anthelmintics only when necessary, employ rotation of anthelmintic every two or three years, use the correct dose of anthelmintics, reduce dependence on anthelmintics and use other management options such as rotational grazing, and adopt strategies to preserve susceptible worms.