Aspiration Pneumonia

Aspiration pneumonia (Image sourced from Bristol Biomed Image Archive with permission)

• Response of the lungs to aspirated foreign material will depend on the nature of the material (e.g. food), the bacterial load and the distribution of the material within the lungs
• Mild bronchopneumonia can develop into a severe necrotising pneumonia and in very severe cases can progress to gangrenous pneumonia (below)
• In Cattle
  • Associated with poor husbandry
  • Regurgitated ruminal content
  • Cranio-ventral distribution
  • Respiratory insufficiency secondary to congenital cardiac disease
• In Horses
  • Most commonly in right ventral lung lobe (most rostral secondary bronchus leads to right accessory lobe)
  • Risk factors:
    • Oesophageal obstruction
    • Spontaneous reflux (GI obstruction, equine grass sickness)
    • Dysphagia
    • Iatrogenic
      • Nasogastric tube in the wrong place
• In Dogs
  • Most commonly vomited/regurgitated material or contrast medium introduced into airways
  • In severe acute cases may die from septic shock
  • In chronic cases -> bronchopneumonia
  • Common sequel to myasthenia gravis, megaoesophagus or persistent right aortic arch