Climate change increases risk of ‘devastating’ exotic equine disease in the UK
Veterinary disease experts considered the effect of changing climate and weather on the risk to the UK equine herd
The threat of exotic equine diseases emerging in the UK is increasing owing to climate change – but there are measures that can be taken.
During a session at the 2026 British Equine Veterinary Association (BEVA) congress titled “Changing climate, changing diseases?” experts considered conditions including West Nile virus (WNV) and African horse sickness (AHS), both of which are notifiable, so must be reported to the Government if diagnosed in this country.
Richard Newton, director of epidemiology and disease surveillance at the University of Cambridge vet medicine department, explained that WNV is maintained in birds and transmitted by mosquitoes, not directly between horses. Its effects range from mild to fatal.
“We are trying to raise awareness among UK vets in terms of this,” he said. “It’s in north Africa and across Europe; it is considered exotic to the UK, we don’t have it circulating as far as we know. But it has been reported at least twice in horses in the UK, first in 2013, then in 2022, and both involved recently imported horses from Europe.”
The second case was in a horse who had been competing in southern Spain, and had to be euthanised.
Dr Newton referred to the fact remnants of WNV genetic material were found in mosquitoes in Britain. No more has been found since “but it’s a warning sign that things could be changing”.
He added that surveillance of mosquitoes is key in planning for any emergence of WNV here, citing a recent case of two German airport workers who died of malaria transmitted by mosquitoes that arrived on a plane. He showed a map showing that WNV appears to be moving further north in Europe, adding: “I think we’re seeing climate change modifying these risks. It’s changing environmental conditions and, I think, changing the ability to sustain insect vectors and transplant disease. So I think we have to be open to that.”
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Action that can be taken
He added: “I’m really just highlighting to UK vets, UK stakeholders, if you’re travelling horses to mainland Europe, there is a risk, but there are things that can be done. You can vaccinate these horses.”
The WNV vaccine is very successful, he said, and its use is strongly recommended for horses travelling to mainland, particularly southern, Europe. Other measures include insect-repelling action such as fly spray and rugs, and considering wetland areas favoured by mosquitoes.
Mike Hewetson of the Royal Veterinary College spoke about AHS, of which he has had experience, a “horrendous disease”.
The insects that transmit AHS are not indigenous to the UK and our temperate climate does not favour them.
“But unfortunately, and as Richard has already mentioned, climate change has altered the status quo,” he said. “You don’t need to look very far to appreciate the very real risk climate change brings.”
Bluetongue concerns
Dr Hewetson cited the recent UK spread of bluetongue virus, which is potentially fatal in sheep and cows. It is similar to AHS and is transmitted by the same midges, blown over from continental Europe.
“But what is unprecedented and extremely worrying is that there’s now evidence of local transmission within the UK, which means our indigenous [midges] are also now capable of transmission of the disease,” he said. “If bluetongue is able to be transmitted in the UK, it’s not hard to imagine that the same could happen if AHS was introduced. The welfare and economic implications of an outbreak of AHS on a naive UK horse population would be devastating, and I don’t think that’s an understatement.”
There is no treatment for AHS and the mortality rate would be 90-95%, he said, adding that there are no licensed vaccines in this country, although one is in development.
“Surveillance is going to be critical, and we as vets will play a really important role in that,” he said. “EIDS [equine infectious disease surveillance] is responsible for surveillance schemes, and will be critical in disseminating that information. So I would definitely encourage you to subscribe to that, and obviously educating horse owners about the clinical signs of AHS will be critical. I think this quote by Peter Tiffany sums it up perfectly: ‘It’s important for horse owners to become educated on transboundary diseases. Don’t expect someone else to be the sole source of your information’.”
BEVA has more information on AHS online, and there is more information about equine disease on the Equine Infectious Disease Surveillance website.
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Eleanor is an experienced journalist who spent over eight years working for local and national newspapers before joining H&H as news editor in March 2016. Passionate about equine welfare and exposing the truth, Eleanor has reported on all aspects of the industry, from Brexit to anti-bullying campaigns, and from dressage rules to mules. Her sport of choice is showjumping, in which she competes her own horses, and she also enjoys reporting at local jumping shows through to international championships.