The letter explains that the use of these two newer groups has more than doubled in the last three years since their reclassification to POM-VPS. Fears that they would be used too widely when the classification changed have proved to be unfounded, but sheep farmers could still harness their potential more.
We would urge more sheep farmers to follow the advice of the Sustainable Control Of Parasites in Sheep (SCOPS) group and integrate the two newer groups into their worm control programmes now.
These products allow lambs to reach their growth potential by removing the build up of worms that have survived previous treatments, and slow the development of resistance to the older three groups of wormers, if they are used in the right way before the older wormer groups become ineffective.
SCOPS guidance encourages all sheep farmers to introduce one of these new groups at only two points in their worm control plan. Firstly as part of their quarantine treatments for all incoming sheep, and secondly as a one-off treatment for lambs, in the latter part of the grazing season.
An effective farm protection (quarantine) treatment is essential to prevent otherwise healthy sheep bringing resistant worms onto the farm. For full details click here
To get the most benefit from the treatment for lambs, it is important that it is used in the latter part of the grazing season (as a mid-late season break dose) when a treatment is deemed necessary (ideally following a significant worm egg count). The purpose of this treatment is to remove worms that have survived previous treatments with one or more of the older wormer groups (1-BZ white, 2-LV yellow and 3-ML clear). Removing this build up of worms left behind in the lambs allows them to reach their growth potential, and has the double benefit of helping to slow the development of resistance to the older three groups. All lambs remaining on the farm should be treated, but to avoid the risk selecting for resistance to the newer group 4 & 5 wormers, it is very important not to “dose and move” lambs to “cleaner” grazing straight away. To avoid this risk simply drench the lambs and return them to the same fields for four or five days before moving them. For more details on mid-late season break dose click here
The mid-late season break dose for lambs and as part of the farm protection (quarantine) treatment are the only generally recommended times to use these newer products. To avoid the risk of resistance developing to the two newer groups they should not be used at other times without detailed advice from your consultant sheep vet.