Link Is Seen Between British Labs and Livestock Virus

British health inspectors combed two veterinary laboratories in southern England on Sunday after it was discovered that the strain of foot-and-mouth disease at a farm four miles away was the same as the one used in the production of vaccine at the facilities.

Environment Secretary Hilary Benn said that the laboratories, which house the government’s Institute of Animal Health and a private pharmaceutical company, Merial Animal Health, were a “possible” source of the virus but that a definitive conclusion had not been reached.

Inspectors will concentrate on security at the laboratories during their search for a possible leak of the virus, Mr. Benn said.

He appealed to farmers to continue monitoring their livestock for symptoms of the disease, and he said a protection zone around the affected farm had been extended to include the laboratories.

In its statement, the environment department said the strain used at the laboratories for vaccine production was “not one currently known to be recently found in animals.”

The relatively early discovery of a possible local source of the disease found in cattle at a farm at Guildford, in Surrey, increased hopes that the British authorities would be able to get the situation under control and avert the panic that engulfed the agriculture industry during an outbreak in 2001.

The Department for the Environment, Food and Rural Affairs said the strain of the virus found at the farm was used in a vaccine batch manufactured last month by Merial Animal Health.

The company is an arm of Merial Ltd., which is jointly owned by the American drug maker Merck & Company and the French company Sanofi-Aventis. Merial Animal Health announced that it was suspending production of the vaccine.

The environment department’s statement said, “The present indications are that this strain is a 01 BFS67 like virus, isolated in the 1967 foot-and-mouth disease outbreak in Great Britain.”

Prime Minister Gordon Brown held another emergency meeting at 10 Downing Street on Sunday morning, the third since the government announced the outbreak on Friday evening.

Mr. Brown, who interrupted his summer vacation to take charge of the crisis, was eager to avoid the economic disaster of the 2001 outbreak, when millions of cattle and other livestock were slaughtered and burned. Tourism also slumped badly that year.

The BBC reported Sunday that an investigation of the government’s Institute for Animal Health after the 2001 outbreak found that the laboratories were “shabby” and below standard. The investigation also found, according to the BBC, that important senior staff were about to leave, creating a dearth of required skills.

But Mr. Benn announced that four farms that had reported cattle with symptoms similar to foot- and-mouth disease had been found not infected, a sign that the disease may not have spread extensively.

Even so, Mr. Benn warned that until the government was confident that it had found the source of the virus, farmers should remain on guard. “It’s very important that people continue to be vigilant,” he said.

The European Commission announced Saturday that it had banned all live animal exports from Britain. Meat and dairy products from the affected region were also banned, the commission said.

On Saturday, the farm in Surrey, about 30 miles southwest of London, where the outbreak was found, slaughtered and then burned the carcasses of 60 cattle. A herd of livestock at a nearby farm was also slaughtered and burned as a precaution, said Britain’s chief veterinary officer, Debby Reynolds.

In some echoes of the consequences of the widespread outbreak of foot-and-mouth disease in 2001, some agricultural shows were canceled this weekend, including in Cambria County, which was badly hit last time.

A major tourist attraction, Woburn Abbey in Bedfordshire, which includes a deer park and a safari park, closed as a precautionary measure.