Mulesing — surgically removing skin folds from around a sheep's hindquarters — is practised in Australia to prevent flystrike, but causes acute pain and is increasingly contested.
Mulesing causes undeniable acute suffering — it is a surgical procedure performed without anaesthesia on conscious sheep. The justification is prevention of flystrike, which also causes severe suffering if it occurs. This is a genuine welfare-versus-welfare dilemma: preventing a potentially fatal parasitic condition through a painful procedure. However, alternatives exist: pain relief at mulesing reduces suffering significantly; breeding programmes for low-wrinkle Merinos reduce flystrike susceptibility; and improved monitoring and insecticide use can also manage flystrike risk.