Respiratory diseases including enzootic pneumonia and porcine reproductive and respiratory syndrome (PRRS) cause widespread suffering in commercial pig production. Prevention through ventilation and biosecurity reduces welfare harm significantly.
Pigs with respiratory disease experience chronic discomfort, reduced appetite, and impaired growth. In severe outbreaks, mortality can be substantial. The conditions that predispose pigs to respiratory disease — high stocking density, poor ventilation, elevated ammonia concentrations, and inadequate biosecurity — are structural problems in intensive pig production. Welfare assessments that include respiratory sound scoring and lung lesion data at slaughter provide objective evidence of herd respiratory health. Addressing these structural causes rather than relying solely on antibiotic treatment is essential for sustainable improvement.