The Sustainable Control of Parasites in Sheep (SCOPS) and Control of Worms Sustainably (COWS) have urged livestock farmers to think twice before applying dips, insecticides or repellents to their livestock in the hope of preventing infection with bluetongue virus (BTV) transmitted by midges.
These products are not licensed for this purpose, and there is no evidence that they can kill Culicoides midges quickly enough to prevent infection or sustain protection against onward transmission.
Nerys Wright, speaking on behalf of SCOPS and COWS, said: “We understand why farmers are concerned and why they want to take some action. However, the evidence is clear: a single bite from one infected midge can transmit BTV, and there are no control or repellent methods available that will protect animals from infection.”
The use of these products also has potential environmental, ecological and resistance impacts. Showering or jetting sheep with organophosphate (OP) products contravenes VMD regulations because they are not approved as effective application methods. For further information, see the statement published by SCOPS in June 2022.
Phillipa Page, president of the Sheep Veterinary Society, added: “Vaccination will protect your flock or herd, and it’s not too late to vaccinate. There are licensed bluetongue vaccines available for BTV-3 and BTV-8 through vets.
“Please discuss this with your vet as part of a farm-specific plan. It is important to remember that full immunity takes time to develop, approximately three weeks in sheep and longer in cattle because a two-dose primary course is needed.
“Vaccination will not provide immediate protection for the current risk period in hotspot areas, but it remains an important option to consider for all farms, as the risk period is likely to continue into late summer.”
Prescribers must remember that insecticidal products cannot be recommended or supplied in a way that implies they will repel midges or protect animals from bluetongue.
Stephen Dawson, AMTRA chief executive, said: “AMTRA echoes SCOPS and COWS in reminding SQPs that recommending or supplying OP dips, insecticides or repellents for the purpose of repelling Culicoides midges or preventing bluetongue transmission is off-label and is not permitted for SQPs.
“These products should not be prescribed, recommended or presented for use against midges. If farmers ask what they can do, acknowledge their concern, explain that the evidence does not support this approach, direct them to speak to their vet, and signpost them to further information and frequently asked questions.”
