Respiratory disease in commercial broiler flocks causes significant welfare harms across millions of birds annually.
Respiratory disease in commercial poultry flocks represents both individual animal suffering and a systemic welfare failure linked to production system design. High stocking densities, accumulated litter ammonia, and poor air exchange create conditions that promote pathogen spread and airway damage. Individual sick birds experience significant distress and often cannot compete for resources in large flocks. Welfare-oriented reforms — lower stocking density, litter management, improved ventilation — address disease burden while also reducing antibiotic dependence.