Sheep Flystrike Treatment and Emergency Response

Blowfly strike in sheep is a rapidly progressing, extremely painful condition that constitutes a welfare emergency requiring immediate recognition and treatment.

Key Facts

Flystrike occurs when blowflies (primarily Lucilia sericata) lay eggs on soiled wool, and hatching maggots begin feeding on living tissue
Maggots can penetrate 3-4 cm into flesh within 24 hours, causing extensive tissue destruction
An affected sheep may die within three days of initial strike if untreated
Breech wool contamination with feces is the primary risk factor, making Merinos and long-woolled breeds most susceptible
Organophosphate or cyromazine insecticide dips provide preventive protection for 8-14 weeks
Post-strike treatment requires removal of all affected wool, maggot removal, wound cleaning, and systemic antibiotic treatment

Welfare Considerations

Flystrike is one of the most painful conditions that can affect sheep. Maggots secrete proteolytic enzymes that digest living tissue, creating expanding areas of wound that generate intense pain signals. An affected sheep becomes withdrawn, stops eating, shows rapid deterioration, and without treatment dies in agony over several days. The welfare imperative for farmers is early daily monitoring during high-risk periods (warm, wet weather) and immediate treatment when strike is found. Prevention through targeted insecticide application is far superior to treatment from a welfare perspective.

What You Can Do

Apply preventive insecticide treatments during high-risk periods (spring to autumn in temperate climates)
Check sheep daily for signs of flystrike including wool matting, discoloration, and behavioral withdrawal
Treat any affected sheep as an emergency — remove struck wool, eliminate maggots, clean wounds, and apply insecticide
Seek veterinary advice for severe cases requiring pain management and systemic antibiotics
Manage breech wool contamination through dagging (shearing the breech area) to reduce strike risk
Consider tail docking using recommended methods and timing to reduce breech contamination in susceptible breeds