Confirmed cases of foot and mouth disease have now risen to 81 across the UK.

Government officials said on Wednesday that four new cases have been confirmed by government vets in England, Wales and Scotland and one case has been found in Northern Ireland. The number of cases being found has remained at five-a-day and have been traced to the original outbreak so MAFF officials remain unconcerned.

Horse racing is set to resume in several areas of the country despite pleas from the farmers union that a further seven-day ban should be put in place to prevent any wider spread of the disease.

Chief veterinary officer Jim Scudamore said at the daily update on Tuesday that the foot and mouth outbreak has not yet reached epidemic levels despite the continued increase in cases. "Each case links back to the original outbreak or neighbouring farms. We've just got to watch and see how it develops. There's been a small amount of lateral spread but at the present moment it looks as though it is under control," Scudamore said.

Agriculture minister Nick Brown confirmed on Monday that MAFF is looking into continuing licences for the manufacture of swill among pig farmers which is how the outbreak is believed to have begun.

"It's one of the things we're looking into at the moment. Clearly that's an issue I expect to be picked up by the debate into how it happened, though we're not making a definitive decision at the moment," he said.

Abattoirs in England and Wales will resume slaughtering livestock which has been cleared under licence from Tuesday and one in Scotland has already resumed work.

Scuadmore revealed on Monday that more than 30 vets were being brought in from overseas to bolster the government's investigation team.

Brown also said claims that troops were being sent to Dartmoor to shoot ponies as a "red herring" because the animals would not be affected. "If there is a red herring story in this crisis then this is it. We're not going to shoot the ponies. At the moment I do not envisage using the armed forces. That's another good story wrecked," he said.

One case had been found at a sheep and cattle farm near Princetown, Dartmoor and this had been traced back to a movement of sheep from a livestock dealer. A team of epidemiologists had been sent to the area to assess the impact on neighbouring farms, the minister said.