Farmers have been urged to stay vigilant after more cattle were found with the bluetongue virus in Kent.

A six-mile temporary control zone (TCZ) was set up around a farm in Canterbury earlier this month after a cow tested positive for the disease.

Through additional surveillance and testing, the chief veterinary officer has confirmed four additional cases of bluetongue virus at two premises in Kent within the TCZ on November 25 – bringing the total to five.

The infected animals will be put down to reduce the risk of onward disease transmission.

Bluetongue is a viral disease spread by insects which can infect sheep, cattle and goats.

Strict rules on the movement of livestock from regions affected by bluetongue are already in place.

Farmers have been reminded that animals imported from these regions must be accompanied by the relevant paperwork to clearly show they meet certain conditions designed to reduce disease risk, such as correct vaccination.

The UK’s chief veterinary officer Dr Christine Middlemiss said: “Bluetongue does not pose a threat to human health or food safety, but the disease can impact livestock farms, and cause productivity issues.

“This detection is an example of our robust disease surveillance procedures in action and it is also a clear reminder for farmers that the disease remains a threat, despite coming towards the end of the midge activity season.

“Farmers must remain vigilant and report any suspicions to APHA.”

According to the Department for Environment, Food and Rural Affairs (Defra), signs of the illness include lethargy, redness of the mouth, eyes and nose and a fever.

Farmers within the TCZ are now being told to prepare to be contacted by the Animal and Plant Health Agency (APHA), which will be carrying out surveillance testing as part of its investigations.

Ruminants – such as cattle, sheep, goats, deer and gazelles – from Britain and Northern Ireland cannot be exported to the European Union or Northern Ireland until further notice.

Bluetongue has also been reported in a number of other European countries.

There is no specific treatment for animals found to have bluetongue other than rest and being well looked after.

Experts say it cannot be passed to humans, with meat and milk from infected animals safe to eat and drink.