Cattle Fly Strike and Summer Welfare Management

Fly strike (myiasis) in cattle causes significant welfare harm during summer months, with the blowfly Lucilia sericata being a major cause of pain and secondary infection.

Key Facts

Fly strike in cattle occurs when blowflies lay eggs in wounds, soiled areas or skin folds — larvae cause progressive tissue destruction
Wounds including dehorning sites, castration wounds, navels and any area of moist dermatitis are primary strike targets
Summer fly pressure peaks in hot, humid conditions, making fly control a seasonal welfare priority from June to September
Ivermectin pour-on and wound sprays containing insect growth regulators are effective fly strike prevention tools

Welfare Considerations

Established fly strike causes rapid welfare deterioration — larvae consume living tissue, creating expanding wounds that cause intense pain and attract further fly activity. Cattle with undetected strike become increasingly depressed, refuse food and show obvious signs of distress. Daily inspection of all cattle for signs of strike is the critical welfare intervention during high-risk periods. Prompt treatment removes larvae and prevents progression; severe untreated cases require intensive nursing care.

What You Can Do

Inspect all cattle daily during summer months, paying particular attention to wounds, skin folds and soiled areas
Apply fly repellent preparations to high-risk areas during peak fly season
Treat any identified strike promptly by removing larvae and applying protective wound spray
Ensure good wound hygiene after husbandry procedures — clean dehorning and castration sites are far less attractive to flies