With the lambing season in full swing, Cumbrian farmers are being asked to be on the lookout for a deadly virus that could affect their livestock.

While the number of confirmed cases of Schmallenberg virus (SBV) continues to grow, vets say the disease is not yet widespread in Cumbria.

However, Kevin Beattie, of Capontree Veterinary Practice, says the problem will worsen in the county next year as more midges, which carry the disease, become infected this summer.

“There are only small pockets and odd cases dotted about, but the disease is likely to be more widespread in this area next year,” warned Mr Beattie.

His prediction comes as industry representatives ask farmers to submit animals with suspected cases for post-mortem examination to enable them to gain “the true levels of the virus”.

The post-mortem diagnostic service at John Warren ABP in County Durham, established by AHDB Beef and Lamb, recently detected the infection on at least four holdings in the North East of England, including Northumberland.

The Animal and Plant Health Agency (APHA) has also confirmed cases of SBV in Devon, Dorset, Cornwall, Somerset, Co Laios and Co Cork but farmers worry the outbreak has already hit much further afield, with many already lambing new-borns with severe deformities.

Lambing flocks across the country have experienced higher than normal losses from deformed lambs, while early calving herds are also yielding calves with congenital defects.

SBV is transmitted by midges which infect sheep, cattle and goats when they bite.

Infected cattle can sometimes demonstrate symptoms of acute disease; however, if infected in the earlier stages of pregnancy, lambs and calves can be born with severe malformations that can make delivery very difficult particularly in those with rigidly fixed limbs that may cause damage to the birth canal.

The disease has welfare implications and at sub clinical levels, can suppress milk production and growth rates. Any infection present on farms now will have taken place last year and there is nothing that can be done to alleviate issues at the moment.

Mr Beattie added that vaccine to protect against the disease is likely to be ready for next autumn.

In the meantime, he says any producers who suspect Schmallenberg can have samples taken from the animal’s umbilical cord or placenta fluid scrapings instead of full carcasses to see if the disease is present. Blood samples can also be taken from the mother of the dead animal.

“At such a busy time of the year when farmers are lambing and calving it is not always easy to transport a whole carcass. This is an alternative way of ascertaining if the disease is present,” said Mr Beattie.

An industry statement said: “We have already heard of a number of cases and mainstream lambing and calving is only just starting. However, the Animal and Plant Health Agency (APHA) hasn’t received many samples so the true extent of the problem is not understood.

“Farmers and vets are being urged to be vigilant through the lambing and calving period. It is very important that, if producers encounter lambs or calves with deformities, they contact their vets so post-mortem examination can be carried out to establish whether Schmallenberg is the cause.

“When APHA suspects SBV they will fund the testing for SBV. Test results, whether negative or positive, allow you to confirm or rule out specific disease issues in that animal and potentially in the wider herd/flock, so there is value to the individual farm in investigation.

“At present there is no vaccine available and it is already too late to vaccinate sheep that are due to lamb this spring or cows due to calve. However, there will be vaccine available this year and further details on when will be confirmed soon. Importantly we need to discover the true levels of the virus as this will determine activity later this year, which will seek to inform what action we need to take to protect against SBV going forward.”

Dr Simon Carpenter, head of entomology, The Pirbright Institute, said: “SBV is transmitted between ruminants by midges at a far higher rate than bluetongue virus and so spreads more quickly through farms. This might also mean that it can be transmitted effectively at lower temperatures and so extend the season during which the virus is a threat.”

There is more information on SBV cases in lambs and calves confirmed by APHA and about the arrangements for SBV testing on the APHA Vet Gateway website: ahvla.defra.gov.uk/vet-gateway/schmallenberg/index.htm .

This information will be updated to show new cases, by county, on a fortnightly basis.