This is the time to check for sheep scab

Now is an ideal time to be on the look out for sheep scab, says Liz Genever, EBLEX beef and sheep scientist.

Although scab is present year round, it is a particular threat between October and March, accordiing to Liz Genever, Eblex beef and sheep scientist.

And with infestations affecting growth rates, body condition, fertility and immunity, it is essential animals are treated appropriately.

“Farmers can often be embarrassed about having scab in their flock, but the embarrassment comes from not treating, rather than simply having the disease.”

Scab can be bought in on purchased stock so sheep must be treated on arrival. “New sheep should also be separated from the main flock for at least 21 days and inspected regularly for physical symptoms.”

And ideally farmers should co-ordinate flock treatment with their neighbours to try and treat all sheep within a couple of weeks.

“Bringing in ewes from the uplands also brings with it a potential risk,” she says.

“Treat these ewes as a separate group and do not mix with the rest of the flock. This will also give the opportunity to monitor for other diseases.”

Hill flocks are more at risk because they are so extensive and not seen regularly, says David Evans of Rural Options. “It is important to regularly monitor ewes bought down from the hills.

“It takes about two months for symptoms to appear after initial contact with the mite and because lesions are mostly found on the flanks and brisket, they can be difficult to see so it is important to check carefully.”

The risk of infection from scab will vary depending on individual areas and your neighbours, says independent sheep vet, Paul Roger.

“It is useful to get commoners together to discuss scab control measures – it is essential to have a joined-up system to look at the disease. By treating your flock, you may prevent a flood of infection, but if you treat and your neighbours do not, infection will trickle past.”

And farmers should carry out an in-depth risk assessment so control measures can be designed accordingly.

“You must have a planned approach to scab control. Treating on an ‘ad-hoc’ basic is ineffective. When treating part of the flock, you are wasting both time and money.”

However, when scab is suspected it is worth confirming it is actually the root of the problem, says Dr Genever. “Lice give similar symptoms so it is worth checking the root cause so appropriate treatment can be administered.”

Scab may be a bigger problem for upland flocks, but it is just as important for lowland farmers, says Mr Evans. “Keep fences up to scratch to prevent contact with neighbouring sheep and consider double fencing to limit spread.”

The gold standard for scab control is using a prolonged action dip, Mr Roger continues. “This is an effective way of controlling scab on a regional basis.

“However, when treating individual animals, it may be easier to use an injectable, but combination injections must be managed effectively to prevent worm resistance.”

Farmers must think widely and consider both endo and ecto-parasite control. And any treatment must be included as part of a flock health plan, he says.