Sheep Bluetongue Virus: Welfare Impact

Bluetongue is a devastating viral disease of sheep spread by Culicoides midges. Climate change is expanding its range in Europe, creating new welfare challenges for flocks.

Key Facts

Bluetongue virus (BTV) is transmitted by biting midges and cannot spread directly between animals
Sheep are most severely affected — cattle are often asymptomatic carriers
Signs include facial swelling, tongue cyanosis, coronary band inflammation, and severe lameness
Mortality in susceptible sheep populations can reach 30-70% during first exposure outbreaks
BTV serotype 8 re-emerged in Northern Europe in 2023-2024, having been absent for over a decade
Multiple vaccines are available but must match the circulating serotype

Welfare Considerations

Bluetongue causes intense suffering: severe facial edema, painful coronary band lesions causing lameness, ulceration of the mouth and tongue, and respiratory distress. Affected sheep cannot eat, drink, or walk normally. Death from respiratory failure and secondary complications follows in severe cases. The acute welfare harm during outbreaks is enormous in affected flocks. Vaccination is the most important welfare intervention — preventing infection entirely avoids all associated suffering. Midge control (housing at dusk and dawn) provides additional protection.

What You Can Do

Farmers in risk areas should vaccinate sheep with appropriate serotype-matched BTV vaccines
House sheep at dawn and dusk during peak Culicoides activity in summer months
Support European surveillance programs that provide early warning of new BTV serotype emergence
Advocate for vaccine availability and accessibility for farmers in newly affected regions