A new animal disease which causes severe birth defects and miscarriages in livestock could spread across the whole of Britain this year, experts warned yesterday.
There have been 276 cases of Schmallenberg virus, including in Cornwall, Devon, Somerset and Dorset, in cattle and sheep on farms across southern and eastern England since early this year.
Adult animals which were infected during their pregnancies last autumn by virus-carrying midges, thought to have blown across the Channel after first emerging last year in the Netherlands and Germany, gave birth to deformed or stillborn lambs and calves this spring.
Despite midges dying off during the winter months, tests since March on around 150 cattle and more than 1,000 sheep belonging to the Royal Veterinary College (RVC) showed a small number of animals which had previously tested negative for the disease have now tested positive.
Two of the RVC’s small herd of alpacas have also tested positive for Schmallenberg.
The results revealed the virus had survived the winter and was still circulating in the UK in the current midge season.
Professor Peter Mertens of the Institute of Animal Health said: “On the basis it spread last year very effectively, I see no reason why it couldn’t spread to cover most of the country this year.”
While the impact varies, with as many as 30% of young being born deformed or stillborn on some farms, the incidence rate is generally low, with around 2% to 5% of flocks or herds giving birth to deformed offspring, chief vet Nigel Gibbens said.
He said: “So far we have seen a relatively limited impact from the disease on English farms and those in the rest of Europe, but we understand that it can be distressing for individual farmers.”
But the veterinary experts moved to quell fears of a repeat of bluetongue, which spread to the UK from the Continent in 2007 and prompted an emergency response of widespread vaccination amid concerns that it could kill 25-30% of the country’s sheep, around 8-10 million animals.
Schmallenberg causes only mild symptoms in adult sheep, cattle and goats, with the main problems including reduced milk in dairy cows, fever and diarrhoea lasting just a few days. They are then likely to be immune to future infection.
For the adult animals “it’s like getting a cold”, said Mr Gibbens.
There is no evidence of any health risk to humans.