The highly contagious disease affects pigs and cattle - but is carried by horses - and could have potentially disastrous consequences for the biggest jump festival of the year.
The farm, about 15 miles from Cheltenham in Stroud, is outside the five-mile 'exclusion zone' designated by the Ministry of Agriculture.
With Monday's meeting at Newcastle already cancelled, the scare has even prompted fears that Aintree's Grand National could be in doubt.
Aintree staff were called in to help neighbouring track Haydock ahead of Saturday's meeting.
Disinfectant was sprayed on the ground and the arriving horses were then led through the area.
Shares in British bookmakers fell on Friday as a result of fears that the Festival, which yields £50m a day in betting turnover, could be called off.
Concern in the racing industry has increased after one point-to-point meeting in Essex this weekend was cancelled because it was close to an affected area.
"If this supposed case is confirmed then we will consider postponing the Festival," said Cheltenham commercial manager Peter McNeile.
"If we get blown off course we have emergency powers at our disposal.
"But we have no connection with the farm whatsoever and our information is that the case of the disease is unlikely to be confirmed."
John Maxse, the public relations manager for the Jockey Club, attempted to reassure racing fans.
Irish ban
"Horses, like humans do not get foot-and-mouth disease but almost anything can be a carrier, be it a horse or a piece of equipment such as a horsebox," he said.
"We are in contact with the ministry hourly and we will respond to any restrictions that are enforced.
"We are not looking forward as far as Cheltenham but concerns about farms could have a geographical effect.
"Each race venue is taking precautions, disinfecting horse boxes as they come in."
The last serious foot-and-mouth crisis in 1967 devastated the sport.
Racing was completely wiped out for three months, along with a number of greyhound meetings.
The Irish Government has already banned all United Kingdom livestock and dairy products after the virus was discovered.
There are no immediate plans, however, to restrict the movement of racehorses between the UK and Ireland.
Extra precautions
Irish Turf Club spokesman Brian Kavanagh said: "It's business as normal - just with extra precautions.
"We have issued advice and precautions, concerning transport and hygiene, to trainers with runners in England.
"Obviously we will be guided by our Department of Agriculture and we are awaiting instructions from them."
On Thursday, French government vets turned back a lorryload of horses heading from Britain to an agricultural show in Paris, while samples were taken from British sheep already at the fair.