Parasitology in the practice laboratory: Part 1

Abstract

of decreased productivity in the United Kingdom (UK), costing the UK national flock an estimated £84 million annually (Nieuwhof and Bishop, 2005). There have been recent reports of changes in UK parasite epidemiology. Haemonchus contortus and Fasciola hepatica are becoming both more common and more widespread; warmer autumns and longer grazing seasons are allowing parasite development to continue to occur later in the year and larvae to overwinter in greater numbers. Nematodirus battus, conventionally seen in young lambs in spring, is being recorded increasingly during autumn. In addition, anthelmintic resistance is now being identified much more commonly in the UK.At least eight UK cases of triple resistance to benzimidazole, levamisole and ivermectin in Teladorsagia have been identified, and experience suggests that the true incidence may be much higher. The sustainable control of sheep parasites in the UK has been considered by an industry and government workshop and the Sustainable Control of Parasites in Sheep (SCOPS) advisory manual produced (Abbott and others, 2004), outlining suggested new parasite control guidelines to minimise the selection for resistant worms. There is a strong argument that cattle enterprises should also be concentrating on avoiding the development of resistance before it becomes a real problem in their sector. They also need to consider other concerns, such as the spread of liver fluke and the control of lungworm in late summer, and in adult animals. Veterinary surgeons dealing with farm animal parasitology need to be able to provide the following services: