Sheep and Cattle Bluetongue Disease Welfare

Bluetongue is a viral disease of ruminants transmitted by Culicoides midges, causing severe oral and limb lesions in sheep and significant welfare harm during outbreaks, with vaccination offering the most effective prevention.

Key Facts

Bluetongue virus (BTV) is transmitted by biting Culicoides midges and affects sheep, cattle, goats, and deer
Sheep are the most severely affected species; cattle often act as reservoir hosts with minimal clinical signs
Clinical signs in sheep include fever, facial oedema, oral erosions, coronitis, and a characteristic blue tongue due to cyanosis
Severely affected sheep are reluctant to move due to coronitis, cannot eat due to oral ulceration, and lose significant weight
Mortality in susceptible naive sheep populations during BTV serotype 8 outbreaks in Europe reached 5-30% in affected flocks
The 2006 BTV-8 outbreak in northern Europe spread rapidly and caused severe welfare harm across millions of animals
Effective vaccines are available for major BTV serotypes; vaccination programmes dramatically reduce clinical disease incidence

Welfare Considerations

Bluetongue causes genuine and severe suffering in affected sheep. Oral erosions make eating painful, coronitis makes walking excruciatingly painful, and the systemic effects of the viral infection cause profound depression and weakness. Severely affected sheep may stand motionless for hours to avoid the pain of movement, unable to access feed or water. The rapid spread of BTV-8 across Europe in 2006-2007 demonstrated how quickly bluetongue can cause population-level welfare emergencies in areas with no prior disease exposure and therefore no pre-existing immunity. Vaccination of sheep populations in high-risk areas before midge activity season is the most effective welfare intervention. Vector control through indoor housing of sheep during peak midge activity provides additional protection.

What You Can Do

Ensure sheep flocks in bluetongue-endemic or high-risk regions are vaccinated annually before midge season
Report clinical signs of bluetongue to your vet and national animal disease reporting authority promptly
Advocate for contingency vaccination stockpiling and rapid deployment protocols in national bluetongue preparedness plans
Support midge surveillance and bluetongue monitoring programmes that provide early warning of new serotype arrivals
Donate to farm animal welfare organisations that provide emergency veterinary support during disease outbreak responses