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Yersinia Infection

Two species of this bacterium occur in the pig's intestine, Y. pseudotuberculosis and Y. enterocolitica. They normally cause no disease but have been associated with minor problems in weaned pigs. The bacteria are often found in the tonsils. It can cause diarrhoea in people.


Weaners & Growers
  • Y. enterocolitica causes inflammation of the small and large intestines with diarrhoea and
  • Y. pseudotuberculosis causes small tiny abscesses throughout the carcass.
  • Inappetence.
  • Mild fever.
  • N/A
  • Rare

Causes / Contributing factors

  • This is a faeces spread disease.


The main significance of the organisms is cross reactions that occur when blood tests are carried out for brucellosis. Pigs carrying the organism are likely to react positively. If this is the case it is necessary to determine the point in the rearing system when exposure takes place and break the cycle by management control. Yersinia are easily grown in the laboratory.

Further Reading

Click on the links below to find out more about this disease, including treatment, management control and prevention information. The top link is the main article on this disease.