FARMERS throughout the UK have been warned to be on the alert for symptoms of foot and mouth disease in their animals, following the discovery of the disease in pigs at an Essex abattoir on Monday.

MAFF put an immediate export ban on live animals and milk and the EU extended this to ban milk products from the UK.

On Wednesday night the exclusion zones round the abattoir and a nearby farm were extended to wider areas of Kent and Essex after an assessment of the most likely areas of spread of the disease. Five-mile zones were in place round four other farms yesterday, including one near Goole, East Yorkshire.

None of the affected animals was imported into Britain; the suspected source is contaminated feed and investigations were continuing yesterday.

The incubation period for the disease is between three and 14 days but the current strain seems to be much faster. It is thought to be a pan-Asiatic strain, type "O", similar to that which caused outbreaks in Asia and the Far East.

The disease, which can affect cattle, sheep, pigs, goats and deer, causes blisters in the mouth and on the feet, leading to excessive salivation and lameness.

Any farmer noticing such symptoms in stock should immediately contact a vet or MAFF animal health office.

l UKASTA has faxed its 350 members with a reminder about precuations to take when visiting farms. The association's members supply the bulk of commercially produced animal feed, certified seed and grain, oilseeds and pulses to farms.