Poor air quality in intensive poultry houses causes chronic respiratory disease in billions of chickens, driven by high ammonia levels, dust, and pathogens in inadequately ventilated sheds.
Chickens in intensive housing breathe air containing ammonia, endotoxins, and dust at concentrations that would trigger workplace safety requirements for human workers. Chronic inhalation causes progressive respiratory tract damage that makes every breath uncomfortable. Birds with respiratory disease show reduced activity, abnormal posture, and labored breathing. Because respiratory disease develops gradually and affects the entire flock simultaneously, it is normalized rather than recognized as a welfare failure. The solutions — better ventilation, lower stocking density, and improved litter management — are known but not uniformly implemented.