Mycoplasma hyopneumoniae causes endemic pneumonia in pig herds worldwide, producing chronic coughing, reduced growth, and compromised welfare in millions of pigs annually.
Mycoplasma pneumonia imposes a chronic, low-grade respiratory welfare burden on affected pigs that is easily underestimated because the suffering is cumulative rather than dramatic. Pigs with endemic mycoplasma experience persistent coughing, breathing effort, and the systemic malaise of chronic infection. Secondary bacterial infections frequently complicate mycoplasma-damaged airways, causing more severe disease. The condition reduces the ability of pigs to compete for food and engage in normal behaviors, compounding welfare impacts through social disadvantage. Vaccination programs reduce severity while herd elimination programs offer the possibility of long-term freedom from this endemic welfare problem.