Sheep farmers are being advised to note new evidence of resistance in sheep scab mites to the 3-ML endectocide products.

The Sustainable Control of Parasites (SCOPS) recommends that sheep farmers only use these products when necessary and carefully follow company instructions.

Lesley Stubbings of SCOPS said: “Sheep farmers should not be alarmed at this stage. A diagnosis is vital in avoiding over-use of scab treatments so, if you think you may have sheep scab, contact your vet who can arrange for a diagnosis. We now also have a blood test that shows whether sheep have been exposed to scab without having to wait to see clinical signs.”

SCOPS urges sheep farmers who suspect that an endectocide treatment may not have been fully effective to check that the dose rate was correct, that the whole group was treated properly, and there’s been no chance of reinfection. They should also report any suspected lack of efficacy to the Veterinary Medicines Directorate (VMD).

Ms Stubbings advises farmers to inform their vet so they can confirm the presence of scab mites and advise on further treatment options.

One option is to remove any remaining mites by plunge dipping in an organophosphorus (OP) although Ms Stubbings warns:

“But remember that an OP dip should not be applied by either a shower or a jetter. Not only is this unlicensed, it’s not an effective treatment against sheep scab.”

SCOPS also recommends that farmers take action to protect themselves, by making sure they quarantine any sheep coming into their flocks, and treat against sheep scab.