Air quality inside intensive pig facilities, characterized by high ammonia, hydrogen sulfide, and particulates, causes chronic respiratory suffering in housed animals.
Chronic respiratory illness in intensively housed pigs is so prevalent it is often normalized as a production condition rather than recognized as ongoing welfare suffering. Pigs with pneumonia, pleuritis, and rhinitis are in pain and discomfort throughout their lives. The air quality conditions that cause these problems — inadequate ventilation, excessive stocking density, slurry accumulation — are design and management choices, not inevitable consequences of pig farming. Facilities that invest in ventilation see reduced antibiotic use and improved performance alongside welfare improvements.