Mulesing involves surgically removing skin folds from around a Merino sheep's breech (rear area) to create a smooth, fly-resistant scar. It is practiced in Australia on approximately 25 million lambs annually. The procedure, typically performed without anesthesia, causes significant acute pain and post-operative discomfort lasting days to weeks.
Flystrike (blowfly myiasis — fly larvae feeding on live sheep tissue) is a severe welfare emergency that can kill a sheep in days. Merino sheep, bred for wool production with excessive skin folds, are particularly susceptible around the breech. Untreated flystrike causes extreme suffering and death. Mulesing dramatically reduces flystrike risk in treated areas.
NSAIDs (meloxicam) and local anesthetics (lignocaine) significantly reduce pain during and after mulesing. Research shows effective pain mitigation significantly reduces behavioral and physiological indicators of pain. Pain relief during mulesing is now a legal requirement in some Australian states. However, uptake in practice remains incomplete.
Several alternatives to mulesing show promise: breeding for bare breeched genotypes (Merino lines with reduced skin folds); chemical agents (clip and crutch; OPTiSEL and similar biopasting products); trap-breeding programs that prevent fly access; and improved blowfly monitoring and targeted insecticide use. No single alternative replaces mulesing completely.
Selective breeding for sheep with bare breeches (reduced skin wrinkling) can eventually eliminate mulesing need. Programs like MERINOLINK in Australia track flystrike susceptibility genetics. Genomic selection is accelerating genetic progress. However, full genetic transition takes decades.
Major fashion brands (ASOS, H&M, Patagonia, Country Road) have committed to sourcing only non-mulesed or pain-relief mulesed wool. These commitments drive farm-level adoption of alternatives and pain relief. International market pressure from Europe and North America is the primary driver of Australian practice change.