Parasites remain the number one cause of mortality in sheep in Ireland. The faecal egg count reduction test (FECRT) is used to evaluate the effectiveness of a worming programme. If the wormer is effective then we see a reduction of faecal egg counts of >95% post dosing. As an option in the Sheep Technology Adoption Programme (STAP), almost 2,000 farmers completed a FECRT in 2013. Alarmingly, the worming failure rate was 49%. Worm control is one of the more basic husbandry tasks on Irish farms and a 49% failure rate represents a serious issue.

There is resistance recorded in all three commonly used classes of wormer in Ireland, so it is a reality that must be managed. This can be achieved with this eight-point plan using the Sustainable Control of Parasites (SCOP) principles.

  • Devise an appropriate control strategy with your vet for sustainable control of worms on your farm.
  • Avoid introducing resistant worms with bought-in sheep. Using a quarantine dose, either by dosing with two actives or using one of the new anthelmintic groups available on prescription, will prevent contamination of your pasture. Bought-in sheep should be kept from your own stock for 48 hours after dosing.
  • Administer wormers effectively. Proper restraint will help to ensure that the dose is delivered to the oesophagus rather than the mouth.
  • Use FEC to identify when anthelmintics are necessary rather than over-using products.
  • Use the appropriate wormer for the job.
  • An FECRT is useful to monitor the effectiveness of worming strategies.
  • Changing from dose and move, to move and dose later, or dosing a proportion of the flock, slows down the development of resistance.
  • Reduce dependence on anthelmintics by rotational grazing and post-grazing sward management, as well as breeding from sheep that exhibit a natural resistance to worm infestations.

    • Conor Geraghty works at Geraghty & Neary Veterinary Surgeons, Mountbellew, Co Galway – part of XLVets. XLVets is a group of progressive practices, working together to achieve a better future for agriculture in Ireland.