Highly pathogenic avian influenza (HPAI) has caused the culling of hundreds of millions of poultry in recent years. The welfare implications of outbreaks and culling methods are significant.
Avian influenza outbreaks create a welfare emergency at enormous scale. The choice is between allowing disease to spread, causing suffering and death throughout an entire flock, and culling to contain the outbreak — causing immediate death to potentially healthy birds in at-risk zones. Minimizing the welfare harm of culling requires humane methods: carbon dioxide or mechanical methods that cause rapid insensibility are preferable to drowning or foam methods that may cause distress before death. The longer-term welfare question is whether the intensive farming systems that facilitate HPAI spread should be reconsidered as part of both biosecurity and welfare strategy.