Five steps to establishing worm resistance
Despite the levels of resistance to the most commonly used doses, farmers should not despair since the standard drenches will still work in some flocks.
Step 1 Plan ahead
Doing a drench test will take up to three weeks to get results back, so make sure you are planning far enough in advance before treating the whole flock.
You also need to get in touch with the lab before you take any samples - they'll send you the proper containers to do the job - postmen are not too keen on dealing with bags of faeces in the post!
There are seven approved labs listed on the Department of Agriculture website charging anything from €7-30 to do the test - a small price to get on top of this problem.
Step 2 Sample pen
When you have the kit, put about 15 lambs in a clean pen for approximately one hour. It must be clean so that you're not contaminating the samples.
You're aiming for samples from about 10 different animals in order to see what's happening throughout the flock, so if you have 15 you're covered in case some don't pass any faeces.