19/08/2024
Reducing the risk of drug-resistant worms in sheep 🐑 🪱
The resistance to sheep wormers is becoming increasingly common across farms in the UK. With 94 % of resistance to white wormers (Group 1-BZ), 68% resistance to yellow wormers (group 2-LV) and 51% resistance to clear ivermectin wormers (3-ML). Without farmers learning when to worm and what with, this issue will only get worse.
You can eliminate the risk of resistance in sheep by:
· Ensuring you are only worming when you need to and with the correct product.
· Doing faecal egg counts every 3-4 weeks.
· Using a quarantine dose on new arrivals with a group 4 (Monepantel) or 5 (Abamectin, Derquantel) wormer. Also, isolating these bought in sheep from your current flock for 3 weeks will ensure resistant worms are not introduced onto your pasture.
· Making sure you are not under dosing by calibrating your drenching gun correctly and always dosing to the heaviest sheep in your flock.
· When worming your flock, ensure that the sheep stay on used pasture for 24-48 hours before moving to clean pasture to stop the risk of infecting it with purely resistant worms.
· Alternating grazing with cattle and sheep helps hoover up contamination and will help with worm infestations.
· Do not wait for clinical signs of a worm burden - the flock could already be affected, and you risk up to a 2.8kg reduction in live weight and 14% reduction in final carcass value. Remember faecal egg counting!
It is worth investing in the correct wormers as an effective worming plan can allow lambs to grow more efficiently and reduce resistant worms on your pasture. By not choosing your wormer correctly, a short-term saving on dosing price could well be outweighed by a long-term reduction in growth rates and more expense in the end. This is because eventually only wormers in the newer groups 4 and 5 will be effective in treating the worm burden in your flock and these are more costly per treatment. The worrying long-term
outcome could be that all worms will eventually become resistant to group 4 and 5 as well. That really would be a resistance problem.
We as SQPs, Vets and Farmers are trying to work together to eliminate this issue before it goes too far.
For any more information on worm resistance in sheep, please visit https://www.scops.org.uk/ or contact Beeston Animal Health on 01829 261361 for any product enquires.
