Mulesing — surgically removing skin from around the breech of Merino sheep to prevent flystrike — is a highly controversial welfare practice that is being phased out in Australia through genetic improvement and alternatives.
Mulesing causes acute severe pain during the procedure and post-operative pain lasting days to weeks. The procedure is performed on young lambs without anaesthesia in standard practice, causing detectable distress. The welfare case for alternatives is strong — breeding programmes producing less wrinkled sheep with lower flystrike susceptibility are progressively reducing the need for mulesing without the welfare cost. Flystrike itself causes severe welfare suffering — maggots consume living tissue causing intense pain and death within days without treatment. The welfare trade-off between the acute pain of mulesing and the risk of flystrike suffering drives the difficult ethical debate, but evidence supports that breeding and targeted prevention can progressively eliminate the need for the procedure.