WITH lambing now under way in many regions of the UK, farmers' minds should already be focusing on worm control in both their ewes and lambs for the forthcoming grazing season. This letter serves as a reminder to vets and advisers who should already have established farm health plans for the coming year and have discussed a worm control plan with their clients. Of immediate concern is what to advise on choice of anthelmintic and when and how frequently to treat ewes during or after lambing. With the emergence of anthelmintic-resistant (AR) nematode strains and the increasing reliance placed on anthelmintics for their control, the continued effectiveness of some of the more traditional worm control strategies has been questioned (Taylor and others 2009) and may influence recommendations on both product choice and application. Dosing of ewes at turnout to pasture is common practice on most sheep farms, with the objective of controlling pasture contamination …