Enzootic Pneumonia - Pigs

Enzootic pneumonia of pigs(Image sourced from Bristol Biomed Image Archive with permission)

• Caused by Mycoplasma hyopneumoniae and Mycoplasma hyorhinis
• Also called mycoplasmal pneumonia
• Major cause of unthriftiness in young pigs
• Pneumonia in weaned pigs
• Cough, reduced growth rate
• Attached to cilia - no mucociliary clearance
• Usually non-fatal unless there is secondary infection (e.g. Pasteurella multocida)
• Gross pathology:
  • Confluent consolidation of the cranioventral lung lobes
  • In other areas there may be small red to grey focal lesions evident which indicate the bronchiolar orientation of the inflammatory process
• Histologically
  • Changes result from a catarrhal bronchointerstitial pneumonia
  • In chronic cases, prominent accumulations of lymphoid cells can be seen around airways and blood vessels