The Schmallenberg virus that has emerged in Britain over the last number of weeks is continuing to push into the western counties of England.
The latest tally for the number farms hit by the new disease released by the British Animal Health and Veterinary Laboratory Agency stands at 92, with cases now reported in 14 separate counties along the east and south coast of England, including Cornwall -- less than 200 miles from the Irish coast.
However, the disease is not a notifiable one in Britain, leading to some unease about the true extent of the outbreak.
"We had a meeting last week about the virus and all the farmers there had seen cases, but only about one in five had actually bothered to report it," Peter Kendall, president of the National Farmers Union (MNFU) said last week. "The number of cases the Animal Health and Veterinary Laboratories Agency is reporting are way under what is happening on the ground."
However, the chairman of the British National Sheep Association, John Geldard, said that he believed the vast majority of farmers were taking a responsible approach to the disease.
"I think farmers are on top of it and I'm hopeful that it will burn itself out in much the same way as Bluetongue did," said Mr Geldard. He claims that the number of lambs being lost even on the worst affected farms is lower than 10pc.
Disease experts believe the virus was spread to the UK by midges that carried it over the English Channel from northwest Europe in the second half of last year.
While British farmers managed to contain Bluetongue, which was the last disease brought over by midges and mosquitoes, Schmallenberg appears to have established itself more quickly in England's coastal areas.
This is a cause for concern, according to an NFU spokesman, since it will be at least a year before an effective vaccine can be developed and distributed to farmers to insulate their animals from the virus. A concerted effort by farmers to vaccinate their stock against Bluetongue in the highest risk areas of eastern England was key in preventing the spread of that disease over the last number of years.
Although Schmallenberg is believed not to be harmful for humans, little is known about the virus at this stage. Cases are only emerging now across Britain as otherwise healthy ewes give birth to lambs suffering from deformities and lack of vigour. Few of the affected lambs survive.
Cattle appear to be able to overcome the condition in a matter of weeks, if not days, after bouts of diarrhoea and fever.
Seven of Britain's 92 positive cases have been diagnosed in cattle, while 85 are in sheep. So far, none of the affected farms have reported importing animals during the past year from the affected areas on mainland Europe.