Prevention key so choose your wormer wisely
Published 20/07/2010 | 05:00
Grazing ground was glad of a bit of rain after the long dry spell, but we've had enough now and need it switched off again.
The lambs are weaned a few weeks at this stage, and dealing with worms, fluke, feet, skin, parasites and vaccinations are on the to do list.
Wet weather and bare pastures help worm numbers to build up as the shorter grass has more eggs and larvae packed on to each leaf. In addition, the moisture stops the worms drying out, so they live longer.
Seek advice and take time when choosing your wormer. The same goes for fluke treatment. Resistance is a very big problem with parasites in sheep. Over-dosing and under-dosing is often seen on Irish farms. When dosing a flock of sheep be as accurate as you can with the weights. Try to avoid setting the gun at one dose rate to treat a full batch.
Their weights will vary a lot and an average weight means that half will be under-dosed, which can lead to resistance. Check with your vet if you suspect resistance to your most commonly used wormer. A simple test involving dung samples after worming can tell a lot.
It is well known that using the same wormer all the time should be avoided. What is less well known is that a lot of brand names are the same product under a different flag.
Another point not commonly considered is how often the wormer should be changed. It is not necessary to change for each treatment. In fact, it is better to change just once a year and then back again to the original, as long as resistance is not already a problem on the farm.