Assessment of anthelmintic resistance in gastrointestinal nematodes of small ruminants, Dale district, Southern Ethiopia

The anthelmintic resistance status of gastrointestinal nematodes of small ruminants owned by smallholder farmers in the Dale district, Southern Ethiopia, was investigated. A faecal egg count reduction test (FECRT) was conducted in traditionally managed and naturally infected goats and sheep. For this study, 60 sheep and 60 goats of both sexes, aged from 6 to 18 months, and with a faecal egg count (FEC) of more than 150 eggs/g of faeces were selected for the test from 5 neighboring kebeles. Both sheep and goats were grouped into four treatment groups: albendazole, tetramisole, ivermectin and control groups. In sheep, the percentage reduction in FECs (95% confidence intervals) for albendazole, tetramisole and ivermectin were 95.0% (86.5 to 98.2%), 97.5% (93.2 to 99.1%) and 96.7% (91.0 to 99.1%), respectively. In goats, the percentage reduction in FECs (95% confidence intervals) for albendazole, tetramisole and ivermectin were 96.6% (88.3 to 99.0%), 97.7% (90.6 to 99.4%) and 97.1% (91.0 to 99.1%), respectively. All the anthelmintics were found to be effective, but resistance to albendazole was suspected.  Based on the findings, it was concluded that development of anthelmintic resistance could be prevented by avoiding frequent dosing and under dosing, while strategic deworming should be practiced by both animal health workers and animal owners.    Key words: Anthelmintics, resistance, faecal egg count reduction, small ruminants, Dale, Ethiopia.