North Yorkshire Commoners take co-ordinated approach to sheep scab
18th November 2022
A farmer in North Yorkshire who grazes his sheep on common land has spoken out about the benefits of testing for scab and the importance of breaking the stigma related to the condition.
John Dawson, Bleak Bank, Settle, is working with other farmers grazing the 1,416ha (3,500 acre) Ingleborough Common, Craven, which at its peak is home to 1,800 ewes, to manage the costly condition.
For the past two years, 12 ewes from each flock have been tested using the blood ELISA test, which detects antibodies in sheep exposed to scab in the last six months. Results have found scab exposure in some flocks, leading to a coordinated treatment approach.
Mr Dawson says: “It’s important we protect each other’s flock. We all are responsible for ensuring our sheep are free from scab, and we must eliminate the stigma attached to it. How you manage a sheep scab diagnosis is important. Any flock can get it and it’s not something to be ashamed of. However, what is important is how you deal with it and to tell your neighbours.”
Each year Mr Dawson buys in two to three Dalesbred tups. Ten years ago, one of the tups he purchased was in quarantine when it began rubbing and losing wool. The vet took a sample and found it to have sheep scab.
Mr Dawson says: “We treated the tup with Cydectin 2% LA for ease as it hadn’t been in contact with any other stock, allowing us to nip it in the bud and prevent it from spreading to any other stock.”
Methods of prevention
Farmers bringing any sheep onto their farm are advised to quarantine them for 3-4 weeks and test 12 animals from each group after two weeks using the blood test. The test costs about £84 for 12 animals. The test will indicate whether the group of sheep has been exposed to scab and whether treatment is necessary, says independent sheep consultant Lesley Stubbings.
“You cannot tell simply by looking at sheep if they carry scab mites. Clinical sheep scab can take weeks, if not months, to present itself, by which time much of the flock can be infected. The Sheep Scab ELISA test means scab can’t hide from us anymore. It makes it much easier for farmers to use the right product at the right time, knocking sheep scab on the head.”
Ms Stubbings says using medicines simply as insurance or ‘just in case’ leads to problems with resistance, but it is also expensive and often doesn’t provide the required control. “By testing, farmers can be sure whether they need to treat or not,” she says.
Available treatments
Farmers can treat sheep scab in two ways:
- Using an injectable group 3-ML such as Cydectin 2% LA has been proven to treat scab infestations and prevent re-infestations for 60 days from a single injection
- Plunge dipping using an organophosphate (OP) dip.
Ms Stubbings says the treatment choice comes down to the most practical method for the farmer, ensuring every animal is treated correctly.
“The main thing when treating for scab is that you do it properly, whether using an injectable or a dip. There’s no reason why you shouldn’t use an injectable, providing it is used properly, meaning the correct dose is administered and all the animals are treated. It is a practical option when there’s only a small number of sheep to treat or if there aren’t the facilities for dipping,” she adds.
Financial and welfare impacts
Scab is such an important condition to control due to the welfare and economic impact it can have, explains Zoetis vet Ally Ward. “Scab is so itchy for sheep, and in the later stages, they will spend all their time rubbing, scratching and biting their wool to alleviate the itching. This is a real welfare concern.”
Figures estimate the cost of sheep scab to the UK sheep industry to be between £78-202 million a year1, with labour being one of the most significant contributors to the cost. Nine per cent of flocks are infected annually, with rates a lot higher in some hotspot areas2.
The Sustainable Control of Parasites in Sheep (SCOPS) group has worked with Zoetis, the makers of Cydectin 2% LA, to produce a Code of Practice for using injectables, which can be found on the SCOPS website: https://www.scops.org.uk/workspace/pdfs/best-practice-use-of-injectable-scab-treatments.pdf
References:
- Nixon, E, J., Wall, R., Vineer, H, R., Stubbings, L. The high cost of sheep scab. Vet Record, October 2020, Volume 187, issue 8 p325.
- Nixon, E.J., Brooks-Pollock, E. & Wall, R. Sheep scab spatial distribution: the roles of transmission pathways. Parasites Vectors 14, 344 (2021). https://doi.org/10.1186/s13071-021-04850-y
