Blowfly strike (myiasis) is one of the most serious welfare emergencies in sheep, particularly during warm, humid periods. Risk assessment and preventive management reduce incidence dramatically.
Blowfly strike welfare is particularly severe because it is simultaneously painful, progressive and often preventable. A struck sheep that is detected early can be treated successfully; one left for 24-48 hours may have maggots deeply embedded causing extensive tissue destruction with severe pain and systemic toxaemia. The welfare obligation is daily observation throughout the fly season - not periodic checks. Farmers who find struck sheep in advanced condition after leaving them unchecked for multiple days have failed a basic welfare duty. Preventive insecticide application timed to regional risk forecasts is effective, affordable and welfare-protective for an entire flock rather than reactive management of individual casualties.