Record bluetongue outbreak ravages UK farms as climate crisis spreads African virus northward

British farmers are living through the worst bluetongue outbreak in recorded history. In just three months—from July through September of this year—the country has documented 2,201 cases of the viral disease. That single figure exceeds the total number of cases recorded across the entire previous three years combined. The virus, which originated in Africa and travels via biting midges, causes fevers, ulcers, and severe swelling in the heads of infected animals. The tongue itself can turn blue and protrude grotesquely from the mouth. In the worst scenarios, the animal dies.

The disease has now crossed into Scotland for the first time, reaching as far north as Aberdeenshire—a geographic boundary that would have been unthinkable a decade ago. Scientists and climate analysts trace this northward march directly to warming temperatures. The World Organisation for Animal Health has linked the virus's spread across Europe over the past two decades to climate breakdown. Academics emphasize that transmission is fundamentally tied to temperature; hotter conditions allow the midges that carry bluetongue to survive and reproduce in regions where they previously could not establish themselves. The particular strain affecting British livestock, serotype 3, first appeared in England in 2023. Now it is accelerating.

Sheep and cattle are the primary victims, though the virus affects other livestock as well. Defra's count of 2,201 cases actually understates the scale of the problem. The agency defines a case as a single premises where at least one infected animal is present, meaning the true number of animals suffering from bluetongue is substantially higher. In September alone, 1,103 premises reported cases—nearly half the season's total in a single month.

Farmers have access to vaccines, but obtaining them has become a logistical nightmare. Robyn Munt, vice-president of the National Farmers' Union, described the vaccine supply as a "demand-led process," meaning farmers must navigate a system stretched to its limits. She emphasized that this outbreak arrives at a moment of acute vulnerability for farm businesses. Many operations have already absorbed unexpected costs from drought and climate-related impacts. Adding vaccination campaigns and potential disease treatment on top of those expenses creates what Munt called "more labour pressure and stress on a farm business." Farmers must maintain what she termed "constant vigilance," regularly inspecting their herds for symptoms of infection.

Tom Cantillon, a senior analyst at the Energy and Climate Intelligence Unit, called this year's record outbreak a "harbinger of things to come." He noted that climate change is making it possible for pests and pathogens once unable to survive in Britain to establish themselves here permanently. The warming trend creates milder winters and hotter summers—precisely the conditions these disease vectors need. Earlier this summer, mosquitoes capable of transmitting Zika virus and dengue fever were discovered breeding in homes in east London, a development experts say signals what lies ahead as the climate continues to warm.

Cantillon stressed a hard truth: vaccination programs for livestock can help manage the immediate crisis, but they cannot address the underlying cause. "We cannot vaccinate against the kinds of climate that encourage these outbreaks," he said. The only genuine solution requires reducing global emissions to net zero and halting warming altogether. Until that happens, the bluetongue outbreak of 2026 will likely be remembered not as an anomaly but as the beginning of a new normal for British farming.