Red squirrels face extinction in most of Great Britain due to squirrelpox virus carried by grey squirrels, with welfare implications for the prolonged suffering of infected individuals and the ethics of grey squirrel management.
Squirrelpox in red squirrels causes progressive and painful skin lesions, limb oedema, and systemic disease — mortality is near-universal once clinical signs appear. Affected animals experience increasing debility over 1-2 weeks before death. Grey squirrels culled as disease vectors face welfare harms from the lethal control methods used (shooting, trapping). The ethics of grey squirrel culling for red squirrel conservation requires balancing welfare of individual grey squirrels against welfare and conservation of red squirrels. Humane lethal methods and targeted deployment minimise unnecessary suffering.