Pig Respiratory Disease: Pneumonia Welfare Impacts in Housed Systems

Enzootic pneumonia and other respiratory diseases cause significant welfare problems in housed pigs, with management, vaccination, and ventilation critical for prevention and control.

Key Facts

Enzootic pneumonia caused by Mycoplasma hyopneumoniae affects a majority of pig herds worldwide
The disease causes chronic coughing, reduced growth rate, and predisposition to secondary pneumonia
PRRS virus (porcine reproductive and respiratory syndrome) causes both reproductive failure and severe respiratory disease
Poor ventilation, high stocking density, and mixing of age groups increase respiratory disease risk
Vaccination against key pathogens combined with good husbandry reduces but does not eliminate disease

Welfare Considerations

Pigs with respiratory disease experience chronic welfare compromise from persistent coughing, breathing difficulty, and reduced lung function. Enzootic pneumonia causes a prolonged cough that affects sleep and rest quality. Severe pneumonia from secondary bacterial infections causes high fever, profound weakness, and respiratory distress that is acutely distressing. PRRS infection causes severe systemic illness with high fever, respiratory distress, and a characteristic blue discoloration of the ears in severe cases. The chronic nature of respiratory disease in housed pigs means that many animals experience ongoing welfare compromise throughout their production life.

What You Can Do

Maintain good ventilation in all pig housing to reduce respiratory pathogen accumulation
Implement all-in all-out management to break disease transmission cycles
Vaccinate against key respiratory pathogens in consultation with your vet
Monitor lung lesions at slaughter as an indicator of respiratory disease welfare burden
Review stocking density and air quality as primary risk factors for respiratory disease
Ensure prompt identification and treatment of individual pigs showing respiratory signs