SHEEP FARMERS are being urged to stop administering organophosphate (OP) dip products on sheep using jetters and showers, largely because it has been shown to be ineffective.

New guidance issued by the Animal Medicines Training Regulatory Authority has been taken up by the Sustainable Control of Parasites in Sheep group (SCOPS), which stressed that plunge dipping is the only way to get the active down to the animal’s skin to effectively kill all the mites.

Its sheep consultant, Lesley Stubbings, pointed out: “There are no veterinary products licensed in the UK for use through jetters or showers. This use has gone widely unchallenged in the past, but the hurdles we face in controlling sheep scab are now so great that SCOPS has welcomed and is now highlighting the importance of following this recently released guidance.

“We already know some sheep scab mites are resistant to the injectable products, which means it is more important than ever to preserve the efficacy of the organophosphate dips. Exposing scab mites to a sub-lethal dose of OP in jetters and showers is an ideal way to encourage resistance to develop and we cannot afford to continue taking that risk,” she added.

“Plunge dipping is the only way to get the OP down to the skin so it can kill all the mites. Showers and jetters simply cannot achieve that, so if you use one of these methods, all the industry bodies involved in SCOPS are united in urging you to stop.”

Chief executive of the National Sheep Association, Phil Stocker, acknowledged that while this message might not be accepted by some, the science could not be ignored: “This tough line on jetters and showers has not been taken lightly. We know farmers and contractors have invested heavily in such equipment – historically they have even been incentivised by grants and loans to encourage their use – and it is very frustrating to be told they should no longer be used.

“But we cannot emphasise enough how important it is to protect the efficacy of OP dips, which are just not suitable for use in jetters and showers.

“I know that abandoning what has long been seen as a useful tool in our armoury, walking away from equipment we were previously encouraging the use of, will anger a lot of farmers and contractors. But NSA and others would not take this hard line if we did not believe the new advice was scientifically sound and absolutely crucial to our future fight against scab.”