British farmers are being warned to check their animals after an outbreak of foot-and-mouth disease among pigs was confirmed.
Five-mile animal exclusion zones were in place around an abattoir and farm, both south of Brentwood, Essex.
The cases were confirmed by Chief Veterinary Officer Jim Scudamore.
A British Ministry of Agriculture, Fisheries and Food spokeswoman said an inspecting vet working for the State Veterinary Service had alerted officials after visiting the abattoir on Monday.
A routine veterinary inspection of animals at the premises had proved "highly suspicious", with suspected symptoms of foot-and-mouth found in 27 pigs.
Farmers within the exclusion limits are being warned to look out for animals either lame or off their feed.
A spokeswoman said: "We need the assistance of the farming community to check their stock and report any potential symptoms, because this does spread very rapidly."
There is no threat to humans, she said.
The infected pigs arrived at the abattoir last week from two farms - one in Buckinghamshire and another on the Isle of Wight.
Exclusions were placed around these farms yesterday.