Avian influenza outbreaks have resulted in the culling of hundreds of millions of birds in recent years, with the methods used for mass culling raising serious welfare concerns.
Avian influenza culling welfare is a genuine emergency management challenge where ideal welfare standards may conflict with the speed required to contain highly contagious disease. Ventilation shutdown is the most controversial method: it kills birds through heat stroke over a period that may take hours and involves extreme suffering. The AVMA classification as conditionally acceptable has been rejected by many welfare scientists as reflecting logistical convenience rather than animal welfare evidence. Better preparedness -- pre-positioned CO2 equipment, trained response teams, and clear welfare-prioritising protocols -- is the investment that could prevent the welfare catastrophe of mass ventilation shutdown in future outbreaks.