Blowfly strike is one of the most painful welfare conditions affecting sheep globally. Prevention is far more welfare-effective than treatment of established cases.
Blowfly strike causes some of the most intense suffering experienced by farmed animals. Larvae consume living tissue causing severe pain, and the affected sheep shows obvious distress behaviors indicating acute suffering. The hidden welfare aspect is that strike is often detected late - sheep may be affected for days before the wound is noticed in extensive grazing systems. Prevention is dramatically more welfare-effective than treatment: chemical prophylaxis, appropriate timing of crutching, and monitoring during high-risk periods prevent suffering rather than responding after it occurs. The mulesing debate exists specifically because strike prevention is so important to sheep welfare.