Porcine Respiratory Disease Complex (PRDC) is a major welfare and economic problem in commercial pig production. Multiple pathogens interact with environmental and management factors to cause chronic respiratory disease that causes lasting harm.
Respiratory disease in pigs causes chronic suffering that affects millions of individuals in intensive systems. The laboured breathing, coughing, and general malaise of chronic PRDC significantly reduce quality of life for affected animals. Many cases are preventable through housing and management improvements - ventilation quality, stocking density, and mixing reduction all have documented effects on disease prevalence. The relationship between respiratory disease prevalence and stocking density provides a direct welfare argument for lower-density housing.