No quick fix for wormer resistance
Lesley Stubbings of Sustainable Control of Parasites in Sheep (SCOPS), warns there is no quick fix for flocks with wormer resistance.
There are no quick fixes for wormer resistance, warns Lesley Stubbings of Sustainable Control of Parasites in Sheep (SCOPS).
She says: “We all like to think there is an easy solution to a problem but, when it comes to wormer resistance, the reality is once it is established on a farm there is no way back.
“When you reach the stage where there are more resistant than susceptible worms on a farm the situation cannot be reversed.
“This is why it is so important sheep farmers act now while they still have enough susceptible worms on their farms. Resistance does not happen overnight. It develops over a number of years and we can slow it right down if we use wormers carefully as well as cutting our reliance on them.
“If you wait until resistance is obvious then it is too late. Acting now, when the number of resistant worms is relatively low, is the only way to safeguard your ability to control worms in the future.”
SCOPS practical recommendations
- Always give an accurate dose. Inaccurate dosing is a major weakness and has a dramatic effect on how fast resistance develops. Underestimating the weight of the sheep, uncalibrated or unserviced guns and poor technique are all major risks
- Choose the right product for the job. Do not use a combination (such as fluke and worm) or a long-acting worming product without getting advice on whether they are necessary and how to use them carefully (such as leaving some sheep untreated)
- Make sure the product you choose is still effective. Use regular post-drench tests to check. Your vet or adviser can tell you how to do this simple check
- Do not treat adult sheep unless it is necessary. Most ewes do not benefit from a pre-tupping treatment. If using an injectable product for sheep scab (an endectocide), make sure the problem has been accurately diagnosed and you get advice on how best to minimise the selection for resistant worms
- Avoid bringing in somebody else’s resistant worms. Follow an effective treatment regime for all in-coming sheep, those bought-in and your own sheep returning from grazing away
- Never worm sheep and put them directly on to pastures which are ‘clean’ or have a very low level of contamination. Either worm and leave them where they are for a few days before moving, or leave 10 per cent of them untreated
- Use one of the two newest wormer groups (4-AD or 5-SI, available from your vet) on all lambs once in the mid/late season. This will minimise the selection for resistance to other wormers used earlier in the same season, helping to maintain the effectiveness of the other groups
- Ask for help. Talk to your vet or adviser about product choices, testing for resistance and how to get the best from your worm control
Visit www.scops.org.uk for information on sheep worming products available and further details on all the points raised