Gastrointestinal nematodes of Ovis aries in Eastern Cape, South Africa and an evaluation of current anthelmintic procedures

Humans have known about helminth infections since ancient times. Today half of the human population is plagued by a nematode infection. Nematodes are responsible for billions of dollars in global crop damage annually and have had devastating effects on the global livestock industry. Due to the lack of a vaccine, and only a handful of approved classes of anthelmintics, nematode resistance has become a serious global phenomenon, and the South African commercial sheep industry has been one of the worst affected worldwide. The current study used fecal float parasitology to determine the nematode species found on a commercial sheep farm in Eastern Cape, South Africa, and the severity of their burden. There were five main species of nematodes found: Strongyles, Strongyloides spp., Trichuris ovis, Nematodirus spathiger, and Haemonchus contortus. The farm had two different populations of sheep – the flock population which were of acceptable wool quality and the stud population which were of superior wool quality. The two populations were compared to each other. There was no significant difference in nematode species present or severity of infection between the two populations. Although the nematode burden of this farm was not as severe as many other South African farms, a discussion of current anthelmintic treatments and possible practices that may improve animal health and wool quality are discussed