12 March 2025
Testing for anthelmintic resistance on Irish farms
Dr. Orla Keane of Teagasc Grange, Co. Meath is part of new project that will test for anthelmintic resistance in Ireland.
Good worm control is a cornerstone of pasture-based beef production and is currently highly dependent on the use of wormers (anthelmintics). However, gut worms are becoming resistant to the products we use to control them. This is known as anthelmintic resistance.
Despite the myriad of products on the market, there are currently only three classes of anthelmintic available for the control of gut worms in cattle: benzimidazoles (white drenches); levamisoles (yellow drenches); and, macrocyclic lactones (clear drenches). Resistance to all three has now been found in Ireland.
The best wormer is the one that kills the worms on your farm. A new project called Managing Anthelmintic Resistance in Cattle Sustainably (MARCS) will start at Teagasc Grange in 2025. This will test for anthelmintic resistance on Irish farms.
More information
Dr Orla Keane featured on a recent episode of the Beef Edge podcast, where she highlighted the importance of reviewing your farm health plan at this time of year and she discussed the MARCS project.
Listen in below:
MARCS is a collaborative project between Teagasc, University College Dublin, Queen’s University Belfast, Animal Health Ireland and the Department of Agriculture, Food and the Marine.
Its aims are to determine the extent of resistance to wormers on Irish cattle farms; identify major risk factors for the development of resistance so we can target mitigation strategies; and use models of worm population dynamics to apply sustainable parasite control to Irish farms. Farmers can participate directly or vets can recruit their clients as participants.
Testing is the only way to know if a wormer is highly effective as other methods identify resistance too late. By participating in the MARCS project, valuable information about the anthelmintic resistance status of your farm or your clients’ farms will be obtained.
The test for resistance is a faecal egg count reduction test (FECRT). This test involves collecting individual faecal samples from a cohort of calves before and after wormer treatment and submission of the samples to the laboratory. A short survey on parasite control practices must also be completed. Full guidance on the testing protocol will be provided and the sample testing will be provided free of charge.
How to participate
If you are interested in testing for anthelmintic resistance on your farm or in recruiting your farmer clients to test for resistance, complete the form by clicking the button below, or contact marcsparasitology@gmail.com
Click here to get involved in the MARCS project.