AS LAMBING gets underway across Pembrokeshire, there is heightened concern that the deadly Schmallenberg virus (SBV) may infect flocks in the county for the first time.

The disease – which causes fused limbs, twisted necks, deformed jaws and stillbirths in sheep, and also affects cattle – emerged on farms in west Wales last year, but there have yet to be any cases reported in Pembrokeshire.

Infection has already been found on more than 1,000 UK farms this year and farmers preparing to lamb flocks in Pembrokeshire admit the virus is a very real source of concern.

Schmallenberg has spread quickly through Wales and there is a worry that many more flocks and herds will become infected.

Wales’ chief veterinary officer, Dr Christianne Glossop, said there was evidence of SBV infection across most counties in Wales.

After the first clinical case in Wales was detected last November there have been a further 11 positive cases.

“These developments mean it is likely that further malformed lambs will be born in Wales in the spring as a result of some ewes being infected with SBV around the time of mating last autumn,’’ she said.

“It is also possible that some cattle were infected around the same time, and we may anticipate calving problems later in the year as a consequence.’’ Malformation in newborn lambs and calves can result in birth complications, and increase the need for veterinary assistance. There can also be associated serious welfare implications.

Catherine Nakielny runs a sheep farm in Carmarthenshire and chairs the Farmers’ Union of Wales’ new animal health and welfare committee.

She urged farmers to work with their vets to get a health plan in place should any newborn lambs or calves display signs of the virus.

Her flock lambs at the end of March and she shares other farmers’ concerns. But as nothing can be done to prevent it at this stage she urged farmers to concentrate on health issues that can be dealt with effectively.

“Fluke is a major problem this year because of the wet weather and that is something that farmers can do something about,’ said Catherine, who is involved in the Welsh region of the National Sheep Association.

A vaccine will not be licensed soon enough to save this year’s lambs and the full impact won’t be known until early April.

There is a reason why the flocks that are lambing now may be affected worse than those to come: the ewes became pregnant in August, when the weather was warm and the midges that carry the virus were at their most prevalent.

However, questions remain about whether those animals that have already been infected once may have developed a natural resistance; and also whether the disease has made some infertile.

Schmallenberg virus was only named a year ago, after the town in Germany where it was first seen. It has since been found on more than 6,500 farm holdings across Europe. The virus is believed to have come to southern England in the autumn of 2011 with plumes of midges, blown across the sea.

However, it passed to native midges in the spring and spread rapidly across the country while the weather was warm and the midges were mobile.