Animals at second Egham FMD farm may have had infection for three weeks

Cattle at Stroude Farm, near Egham, owned by Ernie Ward, were found to have lesions that were 10 days old. This means they may have been carrying the virus for three weeks before disease was discovered on Wednesday.

It also means they probably infected cattle on neighbouring Milton Park Farm, in animals owned by Rob Lawrence, of Hardwick Park farm.

The revelation is likely to raise questions about whether there was sufficient testing done in Surrey before restrictions were lifted after the August outbreaks, and how disease was allowed to go undetected for so long

It also raises concerns that vehicles leaving the farm, which also had 900 pigs, may have spread the disease further. Defra investigators are in the process of tracing movements from the farm to establish where there might be risk of further infection.

Pigs from a neighbouring farm have been culled as a precautionary measure. But vets are said to be confident that disease has not spread outside the Surveillance Zone in place around the Infected Premises.

It is still unclear how the virus reached Stroude Farm. A number of theories are being investigated. These include illegal animal movements and the possibility the virus arrived on a vehicle visiting the farm or Egham Show, which is said to have taken place on a field in which Mr Lawrence's cattle were grazing when infection was found.

There have also been suggestions that wild deer roaming in the Queen's nearby Great Windsor Park may have been carrying infection.