Britain said on Wednesday it would extend a programme aimed at eradicating scrapie from sheep amid fears that the illness could mask mad cow disease in the national flock.
Scientists are investigating whether mad cow disease, or BSE (bovine spongiform encephalopathy), is present in the UK flock, but said late last year that an experiment had been botched when brain tissue from sheep was mixed up with bovine material.
The Department of Environment, Food and Rural Affairs said 60,000 sheep owners would be targeted to take part in the programme, called the National Scrapie Plan.
"The time is now right to extend participation to all pure breeding flocks and to all scrapie-affected flocks," Elliot Morley, animal health minister, said in a statement.
"I urge every eligible sheep farmer to register an interest." The scrapie campaign involves a breeding programme for genetic resistance to the disease, and participating flock owners would be required to breed from scrapie-resistant sheep, which can be identified by genotyping.Scrapie in sheep is a similar type of disease to mad cow, but it is believed to pose no threat to human health and Britain's food watchdog has said consumers should not stop buying lamb.
But scientists have said up to 100,000 more people could die if mad cow disease is spreading through Britain's 40 million sheep flock.Britain first uncovered BSE in 1986 and a decade later linked it to the deadly human disease, variant Creutzfeldt-Jakob disease, which has killed more than 100 people.