The extent of anthelmintic Resistance on Nematodes in communally grazed sheep and goats in a Semi-Arid area of North-west Province (RSA)

Abstract

A survey was conducted to investigate the occurrence of anthelmintic resistance of nematodes in communally grazed sheep and goat herds in the Zeerust area of the North-West Province, Republic of South Africa. The fecal egg count reduction test (FECR%) tests were used to assess the sheep and goat small holder farmers. Efficacy of albendazole, ivermectin and closantel was done on both the treatment and control animals. Anthelmintic efficacy of 80% was considered a threshold for anthelmintic resistance. The FECR% showed that all drugs tested more than 80% effective in most instances, but there were some notable exceptions. For instance in sheep ivermectin and closantel were 78% and 7 1% effective respectively. [n goats, albendazole was 78% and ivermectin was 76% effective. A significant reduction (P<O.O1t) in epg in all sheep and goat herds was observed 2weeks post-treatment with anthelmintics as compared to the control groups where the epg remained high. The relative efficacies of the 3 drugs on each farm and on different farms showed no significant differences (P>0.05) except with few drugs. The occurrence of anthelmintic resistance in the small holder sheep and goat farming sector is a cause of concern. Steps should therefore be taken by policy makers to prevent its further spread and to avoid the development of a situation as on commercial sheep farms where resistance is rampant.