Erysipelas (Diamond Diseases)

Erysipelas is caused by a bacterium, Erysipelothrix rhusiopathiae that is found in most if not all pig farms. It is always present in either the pig or in the environment because it is excreted via saliva, faeces or urine. It is also found in many other species, including birds and sheep and can survive outside the pig for a few weeks and longer in light soils. Thus it is impossible to eliminate it from a herd. The bacterium alone can cause the disease but concurrent virus infections, such as influenza, may trigger off outbreaks. Disease is relatively uncommon in pigs under 8-12 weeks of age due to protection provided by maternal antibodies from the sow via the colostrum. The most susceptible animals are growing pigs, non vaccinated gilts and up to 4th parity sows.


  • Infected faeces is probably the main source of infection, particularly in growing and finishing pens.
  • The organism multiplies in the body, and invades the bloodstream to produce a septicaemia. The rapidity of multiplication and the level of immunity in the pig then determines the clinical symptoms.
  • Wet dirty pens.
  • Wet feeding systems, particularly if milk by-products are used, can become major sources for multiplication of the organism
  • Continually populated houses with no all-in and all-out procedures and disinfection.
  • Water systems that have become contaminated with the organism.
  • Virus infections.
  • Feed back of faeces.
  • The movement of pigs involving mixing and stress.
  • Sudden changes in temperature and warm summer weather.
  • Sudden changes in diet.


  • sick pigs generally run a high temperature (fever)
  • withdraw from the herd and are found lying down
  • Restricted blood supply causes small raised areas called diamonds in the skin. These are clearly defined become red and finally black, due to dead tissue but no abscesses. Most heal in 7 – 10 days.
  • may cause abortion
  • infertility


  • practice good hygiene
  • keep pens dry with good airflow
  • practice the all in all out sysytem
  • avoid the pigs from feeding on faeces