Veterinary Pathology: Pneumonia Types

Suppurative Bronchopneumonia

• Occurs in the cranioventral region of the lungs
• Has a firm texture
• Color changes from red (acute) to grey (chronic)
• Cut surface: contains purulent exudate within bronchi
• Enters the body via the airways
• Caused by:
  • Low-grade bacterial pathogens
  • Mycoplasma
  • Aspiration of bland materials

Fibrinous Bronchopneumonia

• Occurs in the cranioventral region of the lungs
• Has a hard texture
• Color changes from red to yellow to grey
• Fibrin is present on the pleural surface
• Cut surface contains fibrin and necrosis
• Enters the body via the airways
• Caused by:
  • Highly pathogenic bacteria producing exotoxins:
    • Mannhemia haemolytica
    • Actinobacillus pleuropneumoniae
  • Harsh aspirated materials

Interstitial Pneumonia

• Occurs diffusely throughout the lungs
• Has an elastic texture
• Cut surface is meaty
• Gross features
  • Rib imprints
  • Lungs fail to collapse upon opening the thorax
• Enters the body via the airways or the bloodstream
• Caused by:
  • Viruses
  • Toxins
  • Type III Hypersensitivity reaction
  • Toxicants
• Injury primarily occurs in the alveolar wall, specifically the endothelium or pneumocytes
• Histology: Thickening of the alveolar walls
• Difficult to diagnose macroscopically

Granulomatous Pneumonia

• Occurs in multifocal regions of the lungs
• Has a nodular texture (no pus)
• Cut surface contains granulomas
• Enters the body via the airways or the bloodstream
• Caused by:
  • Mycobacterium spp
  • Systemic mycoses
  • Parasitic ova
  • Trapped food particles (starch)
  • Dead parasites

Embolic Pneumonia

• Occurs in multifocal regions of the lungs
• Has a nodular texture
• Enters the body via the bloodstream
• Color is red when acute and pale when chronic
• Caused by:
  • Rupture of hepatic abscesses into the vena cava in cattle
  • Vegetative endocarditis (right side of the heart)
  • Jugular thrombosis
  • Embolic foreign body (hair, septic emboli, etc).

This quiz covers the various types of pneumonia found in veterinary pathology, focusing on Suppurative, Fibrinous, and Interstitial pneumonia. Each type's characteristics, causes, and anatomical features will be assessed. Test your knowledge and understanding of these important respiratory diseases!