Sheep Flystrike Prevention and Welfare

Blowfly strike (flystrike) is one of the most painful and preventable welfare crises in sheep farming. Understanding the causes and prevention strategies helps reduce this serious condition.

Key Facts

Flystrike occurs when blowflies (primarily Lucilia sericata in the UK) lay eggs in moist, soiled wool — larvae then hatch and eat living tissue
Affected sheep experience extreme pain as maggots burrow into the skin — death from shock or systemic infection can occur within days
The condition is most common in late spring to early autumn when fly populations peak
Dags (dried feces stuck to the fleece around the tail) are the primary attractant for egg-laying flies
Prevention includes dagging (removing soiled wool), preventive insecticide treatment, and genetic selection for fly-resistant traits
Sheep that are sick, have foot rot, or are in dirty conditions are at significantly higher flystrike risk

Welfare Considerations

Flystrike causes some of the most extreme suffering of any condition in farmed sheep. An affected animal may have thousands of maggots burrowing into living tissue over several days before being discovered. Regular inspection — at minimum twice daily during high-risk periods — is the most important preventive measure. The pain caused by flystrike is severe, and early treatment, including maggot removal, wound cleaning, and systemic antibiotic therapy, is essential for welfare. Preventive treatment of high-risk individuals (young lambs, sheep with dags or foot rot) is strongly recommended by all sheep welfare authorities.

What You Can Do

Inspect all sheep at minimum twice daily during the fly season (April to October in the UK)
Keep fleeces clean by dagging around the tail before fly season
Apply preventive insecticide treatment to high-risk individuals at the start of fly season
Treat any confirmed flystrike case immediately — remove all maggots, clean the wound, and consult your vet
Support farm assurance schemes that audit flystrike inspection and treatment protocols