Anthelmintic resistance in Northern Ireland (III): Uptake of 'SCOPS' (Sustainable Control of Parasites in Sheep) recommendations by sheep farmers

Reports of anthelmintic resistance to multiple drugs in individual parasite species, and in multiple parasite species across virtually all livestock hosts, are increasingly common. A working group of UK researchers and practitioners devised a set of guidelines in 2003 (Sustainable Control of Parasites in Sheep, 'SCOPS') aimed at maintaining anthelmintic efficacy on farms. Over the years that followed, these guidelines were promoted through meetings, promotional literature and the agricultural press. Results from questionnaires conducted in Northern Ireland (NI) in 2005 (covering 1999-2004) and 2011 (covering 2008-2011) have provided an opportunity to examine the extent to which these campaigns have influenced parasite control on sheep farms.The percentage of flocks at risk of under-dosing through inaccurate weight estimation in NI has increased by 15.9% since 2005. The number of flocks at risk of under-dosing through non-calibrated equipment has increased by 14.3% since 2005. The size of the in refugia population may have potentially doubled, as indicated by an increased compliance with the recommendation (wherever possible) to leave a portion of the flock untreated. However, whether this is indeed the case cannot be explicitly determined without a measure of the impact of various factors, including host immunity, environment/climate, previous anthelmintic treatment and the species of parasite present.