FieldDxPasteurellosis of SwineClinical signs, differential diagnosis, treatment and prevention in pigs.
Overview
Bacterial bronchopneumonia of pigs, usually secondary to another respiratory infection. Pasteurella multocida, typically complicating mycoplasmal pneumonia, swine influenza, Aujeszky's disease or Bordetella bronchiseptica infection.
Clinical signs
- Exudative bronchopneumonia, often secondary to mycoplasmal pneumonia, swine influenza, Aujeszky's disease or Bordetella bronchiseptica infection.
- Pericarditis and pleuritis in some cases; chronic thoracic lesions and polyarthritis develop with ongoing disease.
Predisposing factors
- Enzootic pneumonia is the most common setting, with pasteurellosis developing as a complication.
- Influenza, Aujeszky disease and infection with Bordetella bronchiseptica or Haemophilus parahaemolyticus can damage the lungs and open the way.
- Pasteurella multocida is a normal upper respiratory resident that becomes an opportunistic secondary invader.
Treatment
- Early, vigorous antibiotic therapy, sometimes combined with sulfonamides, to prevent chronic sequelae; increasing antimicrobial resistance among Pasteurella isolates should be considered when selecting a drug.
- Because the secondary pneumonic form usually follows mycoplasmal pneumonia, control also depends on preventing or managing that primary infection.
Prevention
1. Prevent or control the underlying enzootic pneumonia through good management. 2. Apply biosecurity measures. 3. Start antimicrobial treatment early and aggressively, alone or with sulphonamides, to prevent chronic sequelae; pasteurellae have shown antimicrobial resistance.
Source
MSD Veterinary Manual — Pasteurellosis in Pigs (accessed 2026-08-11)
MSD Veterinary Manual — Pneumonic Pasteurellosis in Pigs (accessed 2026-10-29)
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