Farm Animal Welfare

Sheep Blowfly Strike Prevention and Management

Blowfly strike is a painful and potentially fatal condition in sheep caused by flies laying eggs in moist fleece, with larvae causing severe tissue damage.

Key Facts

Blowfly strike is one of the most painful conditions in UK sheep farming
Lucilia sericata (greenbottle) is the primary blowfly species responsible for strike in the UK
Flies are attracted to fleece soiled by urine, faeces, wounds or fleece rot
Larvae burrow into the skin causing deep tissue damage within hours
Prevention includes crutching, dagging, insecticide treatment and genetic resistance breeding

Welfare Considerations

Blowfly strike causes intense pain, toxaemia and death if untreated. Affected sheep show agitation, biting at the struck area and separation from the flock. Early identification through daily checks during the fly season (April-October) is critical. Preventive insecticide products provide protection for 8-16 weeks and significantly reduce welfare incidents.

What You Can Do

Check sheep daily during the fly season, especially around tail and shoulders
Apply preventive treatments before the fly season begins
Crutch or dag sheep to remove fleece soiled by urine and dung
Contact your vet immediately if you find a struck sheep