Respiratory disease is one of the most significant welfare and production problems in commercial pig farming, caused by a complex of pathogens exacerbated by poor ventilation and high stocking density.
Respiratory disease causes prolonged suffering for affected pigs - coughing, difficulty breathing, fever, and reduced appetite over days to weeks. The welfare costs are substantial given that PRDC affects millions of pigs annually. Vaccination reduces but does not eliminate disease burden; the most effective prevention combines vaccination with excellent ventilation, appropriate stocking density, and all-in all-out management. The economic drivers to control respiratory disease align with welfare incentives - sick pigs grow poorly - but welfare monitoring through slaughter surveillance provides an additional accountability mechanism that benefits both productivity and welfare.