A SURVEY OF ANTHELMINTIC RESISTANCE ON 10 SHEEP FARMS IN MASHONALAND EAST PROVINCE, ZIMBABWE

A survey to detect anthelmintic resistance in nematode parasites of sh eep was conducted on 10 randomly-distributed farms in the Chivhu Distr ict, Mashonaland East Province, Zimbabwe. Before the survey, a questio nnaire was circulated to the farmers concerning nematode parasite cont rol. Results showed that parasite control using anthelmintic treatment was the only method practised and that the benzimidazoles were the mo st frequently used anthelmintic drugs. The faecal egg count reduction test was used to detect resistance. The anthelmintic groups tested wer e benzimidazoles, levamisole and ivermectin. Resistance to benzimidazo les was detected on 6 of 10 farms and levamisole resistance on 2 of 3 farms. Ivermectin resistance was not observed on the farms surveyed. P ost-treatment larval cultures indicated that Haemonchus contortus surv ived administration of fenbendazole, albendazole, oxfendazole and leva misole. A Cooperia sp. strain resistant to albendazole was detected an d this is the first report in Zimbabwe of a resistant parasite in this genus.