DEFRA officials and local vets are urging horse owners near the site of where an animal tested positive for the deadly Swamp Fever virus not to panic.

Veterinary practices have been inundated with calls from residents of Highampton concerned that their animals may have been infected with Equine Infectious Anaemia (EIA) or 'Swamp Fever' following the outbreak at Hole Station Campsite. One horse tested positive and was destroyed on Saturday but Defra confirmed this week that two other horses on site have tested negative for the disease, which can be spread through blood or other bodily fluids or by a biting horse fly.

The horses will be tested again in 90 days with restrictions remaining until then as a precaution.

Local horse owners were angry that they had no contact or direct information from Defra, who posted official warning notices at the campsite at the weekend.

A Defra spokesman said on Tuesday that there was a 'very low risk' the virus would have been passed on.

'In the vast majority of cases of this disease it is passed on through blood or other bodily fluids,' he said. 'It can also be passed on through a horse fly but their maximum travelling distance is around 200 metres.

'The likelihood of a biting horse fly being interrupted and travelling very quickly to carry on feeding on another horse is very small. I would say the risk of it being passed on in this way is very low.'

The spokesman said that Defra was giving advice on its website and through the media but had a long standing policy of not revealing the location of any infected premises because it did not want to discourage anyone coming forward if their animals showed signs of the disease.

It became obvious however, of the location, when signs were posted on the gate to the campsite and on the nearby bridlepath.

It is understood that the infected animal came into the country two years ago showing no signs of the disease, which can lay dormant for long periods of time, and was travelling on a Belgium passport. Defra said an investigation had been launched to find out the origins of the disease in this animal.

Stephen Wildman of Wildman Equine Veterinary Practice in Okehampton said people should not be worried that it was 'Foot and Mouth' all over again. Highampton was at the centre of the outbreak in 2001 which caused devastation across the area.

'Foot and Mouth would carry on the wind. It is strong and long lasting but EIA needs a carrier and it takes a while to spread. If anyone is concerned I would recommend they have a simple blood test done.'

British event rider Lucy Wiegersma, who keeps 60 horses at Acquila Equestrian Centre at Warren Farm, a mile from the outbreak, said it was good news that the tests on the other two horses at Hole Station Campsite this week came back negative.

'We are reassured by these tests and reading the information about how this disease is spread but Defra has been decidedly non informative. We did not hear a squeak despite the signs going up at the infected premises on Saturday. Had we been given the full informative there would not have been so much panic.'

A neighbouring resident to Hole Sation Campsite said she kept animals herself and a lot of horses used the bridlepath which very close to the infection: 'I was astounded no-one came around to tell us about the outbreak or give us any advice. Defra could have been a lot more helpful.

'It really was a shambles. Defra just said the outbreak was in Devon so everyone in the county was worried.'

Two other cases of swamp fever have emerged this year in Wiltshire and Northumbria. It has been likened to the HIV virus in humans and attacks the immunity system.