Mulesing, the removal of skin folds from merino sheep to prevent flystrike, remains controversial due to the acute pain it causes and the availability of alternatives.
Mulesing causes acute and prolonged pain in sheep. Lambs typically show pain behaviours for hours to days after the procedure, and wound healing takes several weeks. The justification for mulesing is prevention of blowfly strike, which itself causes severe welfare harm through tissue destruction, shock, and death if untreated. The welfare trade-off is genuine: untreated sheep in high-risk environments face potentially more severe suffering from flystrike than from mulesing. However, alternatives including chemical preventatives, selective breeding for smooth-bodied sheep, and intensive monitoring have demonstrated that mulesing can be phased out without welfare compromise from flystrike. The trend is clearly toward alternatives.