Farmers urged to heed advice on sheep wormers

Efforts to encourage farmers to combat the growing incidence of resistance to sheep wormers around the country are being redoubled following the confirmation this week of the first case of resistance to monepantel (Zolvix) in the UK.

The breakdown of what wasseenasakeyproductin reducing resistance issues is a “timely and important reminder” to sheep farmers and their advisers, the industry-backed Sustainable Control of Parasites in Sheep (SCOPS) group claimed yesterday.

Speaking for the group, sheep consultant Lesley Stubbings said not only did the breakdown highlight the need for sheep farmers to follow best practice advice, but it also revealed the dangers of not integrating the newer wormer groups into onfarm control programmes before the other wormer groups failed.

She said she understood that the farm where the breakdown had occurred already had resistance to the white, yellow and clear wormers, which meant they were relying on the 4-AD (orange) group alone for worm control.

She said: “Coupled with animals being moved to low challenge pasture following treatment, which is highly selective for resistance, there was the risk of a ‘perfect storm’ in terms of the development of resistance.”

Other sheep farmers, she said, could avoid this situation by following SCOPS guidelines on the use of the 4-AD and 5-SI (purple) wormers.

“SCOPS has been advising that the group 4-AD and 5-SI wormers should be carefully incorporated into control programmes on sheep farms for the last eight years [since Zolvix was launched] as a quarantine drench and a mid/ late season treatment for lambs.

“That advice was given in order to avoid this sort of situation where the other three groups are no longer effective and the group 4-AD is relied upon.”

This meant that the two newest wormer groups should be incorporated into worm control programmes on all sheep farms, not left “on the shelf ” until the others were no longer effective.

She said that the real value of these two new groups lay in prolonging the life of the existing white, yellow and clear wormer groups.

According to Stubbings, without veterinary advice to the contrary, there were two occasions when the orange or purple wormers should be used – at quarantine and mid/late season as a “one off ” annual drench for lambs.