TESTS were continuing last night into a possible outbreak of a disease which could bring fresh heartbreak to the region's pig farmers.

But although it will be another 24 hours before the results are known, it is now considered increasingly unlikely that the industry is about to be plunged into more chaos.

A farm in North Yorkshire is one of six across the country where animals are being tested for Aujeszky's Disease, the symptoms of which include shivering and lack of co-ordination. The disease can be fatal to piglets.

Also known as pseudorabies, the last known outbreak in this country was in 1979.

A programme of slaughtering followed and the country was declared free of the disease in 1989.

But last week, at the Essex abattoir where foot-and-mouth was first found last year, serological tests for Aujeszky's proved positive in six pigs.

Further tests have still to be completed to confirm its presence.

Last night, Stewart Houston, a farmer from Bedale in North Yorkshire and chairman of the food producer group of the National Pig Association, said: "No signs of it have been found on the farms and it's beginning to look as if the original tests are a case of 'false positives', which can happen.

"We were extremely worried at the end of last week but I feel a lot more comfortable about it now.

"However, we are not expecting the final test results until Tuesday."

Remaining free of the disease is regarded by the agricultural industry as crucial for its lucrative export of breeding boars.

Aujeszky's is nowhere near as virulent as foot-and-mouth or classic swine disease.

Mr Houston said: "This underlines the message of meeting biosecurity measures on the farm and through the supply chain.

"It also highlights the critical nature of traceability."