Brachyspira hyodysenteriae

• An anaerobic spirochaete.
• Causes swine dysentery.
  • Infection is acquired via contaminated faeces
  • Disease spreads slowly through the herd
  • Dogs, rats, mice and flies may act as transport hosts
  • B. hyodysenteriae survives several weeks in moist faeces

• Clinical signs
  • B. hyodysenteriae causes dysentry in weaned pigs 6-12 weeks old; pigs lose condition and become emaciated; appetite is decreased; large amount of mucous may be present in the faeces; low mortality; poor feed conversion ratio
• Diagnosis
  • History, clinical signs and gross pathology
  • Anaerobic culture on blood agar with added antibiotics for at least 3 days
  • B. hyodysenteriae causes complete haemolysis whereas other spirochaetes cause partial haemolysis
  • Immunofluorescence, DNA probes and biochemical tests
  • Serology using ELISA can be used on a herd basis
  • PCR