Government vets have changed their approach to tackling bluetongue in livestock - as midge activity is much lower at this time of year, according to industry body Ruminant Health & Welfare.

The vets have found cases of the disease - which is carried by some midges which then infect ruminants with it - in Norfolk, a small part of Suffolk and in Kent and temporary control zones have been put in place restricting movements.

It is thought midges infected with the strain found -  BTV-3 - were carried over the English Channel by wind conditions in autumn. 

Dr Marion England, Institute Fellow in Vector Ecology at The Pirbright Institute, said the Department for Environment, Food and Rural Affairs (DEFRA) has changed its disease control measures in response to being in a seasonally low period for midge activity.

“The current weather conditions and time of year mean that Culicoides – the type of midge able to spread viruses, such as BTV-3, are highly unlikely to transmit the virus to livestock,” she said.

“Under these conditions, midges previously infected with BTV-3 are currently highly unlikely to transmit the virus.

“The most active period for midges is during the warmer months in spring, summer and autumn, and midges can become newly infected with bluetongue virus and spread disease when the weather is above 12C for a sustained period.

“Midges infected in late autumn 2023 are now not likely to be a risk for spreading disease because they usually die off during winter, and are not actively biting when temperatures are below 4C."

Because of the reduced risk of transmission between midges and animals, DEFRA has taken the decision not to cull infected animals where test results indicate older infection and the presence of BTV-3 antibodies, said Ruminant Health & Welfare.

Infected animals may still be restricted at their current locations and other disease mitigation measures taken as appropriate.

For the latest update on BTV-3 and restrictions visit the Ruminant Health & Welfare bluetongue hub at https://ruminanthw.org.uk/bluetongue-virus/.

In the UK, bluetongue, including BTV-3, is a notifiable disease, so anyone suspecting the disease must take action and report it to the Animal and Plant Health Agency (APHA).