RH&W PRESS RELEASE – 20 October 2026
Farmers are being urged to speak to their vets about bluetongue vaccination this winter, as infected midges could continue spreading the virus until January.
With continued cases of bluetongue serotype 3 (BTV-3) and the potential for a mild autumn to extend midge activity, livestock farmers are being warned not to assume colder weather means the risk has passed.
Dr Marion England, fellow in vector ecology at The Pirbright Institute, says infected midges can continue transmitting bluetongue long after temperatures have started to fall.
“You could still get new infections from infected vectors right the way through until potentially the beginning of January,” she says.
Although the virus needs average daily temperatures of above approximately 12°C to replicate within midges, those already infected before cooler weather sets in can continue transmitting for as long as they survive.
With winters becoming increasingly warmer, Dr England explains that the period of low midge activity has also become shorter over the past few years, potentially leaving farmers with less time to prepare for the next BTV-3 transmission season.
“Midges used to disappear around November, but in the past few years they’ve continued through to the end of December or beginning of January so we’re getting a shorter window of reduced disease transmission.”
She adds that despite the exceptionally hot and dry summer, Pirbright’s monitoring has found no obvious reduction in midge populations.
“The populations have been normal all the way through this year, so there hasn’t been any kind of obvious effect of drought on the midges.”
Fertility focus webinar
Farmers who have questions about vaccinating or any perceived impact on fertility, should speak to their vet about the risks of infection and the most appropriate vaccination strategy for their livestock.
Cattle and sheep vets on the Ruminant Health and Welfare bluetongue working group hear there is a lot of misinformation circulating about vaccination and advise farmers to speak to their vet or an expert when making decisions about protecting your flock or herd.
For industry insights related to the impact of BTV-3 on sheep and cattle fertility, and practical guidance from farm vets, farmers and vets are being invited to the next Battle Bluetongue webinar.
The session will be held from 5pm – 6pm on 21st October and is free to attend.
Book on to the webinar via: Bluetongue virus update – fertility impact | AHDB