Pyothorax

• Also called thoracic empyema
• Purulent effusion in the pleural space
• Most significant in:
  • Horses
    • Usually secondary to pneumonia or lung abscesses
    • Streptococci are most commonly isolated
    • Usually yellow exudate
    • Often triggered by stress of travelling, competition or similar
  • Dogs
    • Often results from migrating grass awns
    • Actinomyces, Nocardia and Bacteroides spp. are the most frequently recovered organisms
    • Usually blood stained viscous or creamy exudate, often bilateral
    • Yellowish granules may be present within the exudate
    • Thickened pleura, sometimes fibrinous
  • Cats
    • Pathogenesis is unclear, possible due to bite wounds or penetrated oesophagus
    • P. multocida and other Gram-negative organisms are frequently recovered
    • Usually creamy yellow or greyish brown exudate, often bilateral