The Efficacy Of Commonly Used Anthelmintics Against Gastrointestinal Nematodes Of Sheep And Goats In Morogoro

A study was conducted to determine the efficacy of selected anthelmintics in the control of helminthosis. It aimed at determining the efficacy of benzimidazoles to which some nematodes had developed resistance, the efficacy of levamisole recommended to replace benzimidazoles, and the efficacy of anthelmintics in farms where such replacement had not been recommended. Two farms at Mkundi and Magadu farm were used in the study. In each farm animals were divided in three groups; untreated control group; a group treated with albendazole (Tramazole®) for Mkundi farms and fenbendazole (Fenzol®) for Magadu farm; and a group given levamisole (Levacide®). Faecal samples were collected before (1-2 days) or after (10-14 days) treatment for faecal egg counts and cultures. The anthelmintic efficacy was determined by faecal egg count reduction test, FECRT. Faecal culture established Haemonchus, Oesophagostomum, Trichostrongylus, Cooperia, Strongyloides and Bunostomum as nematodes affecting the three farms. There was development of anthelmintic resistance to levamisole against Haemonchus, Oesophagostomum and Trichostrongylus spp at Magadu farm and Haemonchus and Trichostrongylus spp at Mkundi farms. Despite the 18 years of replacement with levamisole the benzimidazole resistant Haemonchus strain has not shown any sign of reversion to susceptibility. Tanzania Veterinary Journal Vol. 25 (1) 2008: pp. 31-39