Porcine respiratory disease complex is the leading cause of disease-related death in commercial pig farms, causing significant suffering and economic loss.
Pigs suffering from respiratory disease complex experience significant and often prolonged suffering. The combination of viral and bacterial pathogens causes pneumonia, pleuritis, and chronic breathing difficulty — conditions that cause pain and distress. Affected animals are lethargic and reluctant to move to feed and water, leading to secondary malnutrition. The intensive conditions that drive PRDC — high stocking density, inadequate ventilation, and the constant stress of crowded indoor housing — are the same conditions that define conventional pig farming. Preventing PRDC requires systemic changes to housing conditions rather than simply treating outbreaks. Vaccination programs reduce severity but do not substitute for welfare-friendly housing. Outdoor and deep-litter systems show significantly lower PRDC prevalence.