Sheep Ectoparasites: Blowfly Strike and Lice Welfare

Key Welfare Facts

Blowfly strike is one of the most severe and distressing conditions affecting UK sheep, occurring in warm summer months.
Lucilia sericata larvae feed on living sheep tissue, causing intense pain, tissue destruction, and rapid deterioration.
Animals can die within days if strike is not detected and treated promptly through intensive daily observation.
Preventive treatments including insect growth regulators significantly reduce strike incidence during the season.
Dagging, dipping, and shearing reduce soiled and fleece conditions that attract egg-laying flies.
Louse infestations cause chronic irritation, wool damage, and welfare compromise requiring treatment during housing.

Welfare Assessment

Blowfly strike is a preventable welfare emergency requiring proactive prevention and daily observation during the strike season. Farms with good strike management programmes using modern prevention products have dramatically lower strike rates and welfare incidents.

What You Can Do

Implement preventive insect growth regulator products before fly strike season begins
Conduct daily checking of all sheep during warm weather periods throughout summer
Remove sources of fleece soiling through dagging and maintain good bodily cleanliness
Treat any struck sheep immediately and seek veterinary advice for severe cases