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This is a disease caused by a bacterium called Eperythrozoonosis suis which attaches to the surface of red blood cells and sometimes destroys them. The pig may then become anaemic and the products left after the destruction of the cells may cause jaundice. Clinical disease is more commonly seen in young growing pigs. However it can also cause reproductive problems in the breeding herd. A sow may carry Epe and yet remain quite healthy, however, it can cross the placenta resulting in weak pale pigs at birth.

Epe is present in most if not all herds but the mechanisms which allow it to become pathogenic and produce disease in some populations and not in others are unknown. The incidence of disease is low.



Acute disease:

  • Affected sows are inappetent with fever 40-42?C (105-107?F) when high numbers of organisms are present in the blood. This clinical picture is often seen after farrowing.
  • Anaemia
  • Increased respiration.
  • Anoestrus.
  • Pale skin
  • No milk - agalactia.
Chronic disease:
  • Sows become debilitated and pale with jaundice.
  • Poor conception, repeat matings and anoestrus.
  • Delayed returns to oestrus.
  • Anaemia.
  • Jaundice.
  • Bleeding into tissues.
  • Abortion.
  • Thin sows.
  • Stillbirths.
  • Reduced conception rates.
  • Pale skin
  • No milk -agalactia.
  • In severe cases jaundice may result.
  • Secondary infections tend to occur.
  • More chronic cases result in slow growth and poor-doing pigs.
  • Pale and anaemic pigs.
  • Increased scour (sloppy diarrhoea).
  • Pneumonia.
Weaners & Growers

The clinical picture varies:

  • In weaners the acute disease is manifest by primary anaemia.
  • In growers it leads to slow growth and poor-doing pigs.
  • The presence of anaemic and possibly slightly yellow-skinned recently weaned pigs.
  • Pale pigs.
  • Slow or variable growth.
  • Ear necrosis.
  • Enteritis - sloppy diarrhoea.
  • Fever.
  • Pneumonia.
  • Poor pigs, wasting, hairy.
  • Pot bellied pigs.
  • Scour.

Causes / Contributing factors

  • Biting insects.
  • Internal parasites
  • Lice or mange mites.
  • Cannibalism / vice (Abnormal behaviour).
  • Sows method of spread:
  • Vaccinating sows with the same needle.
  • Tagging gilts.
  • Feeding placenta or farrowing house material.
  • Fighting.
  • Vulval and tail biting etc.
  • Piglets - method of spread:
  • Tailing, tooth clipping and iron injections.
  • Weaners & Growers method of spread
  • Fighting.
  • Tail biting and other vices.


In trying to arrive at a diagnosis, the following should be considered.
  • The clinical picture.
  • The identification of the organism in blood smears stained with Wright's stain. Fifty microscopic fields should be examined before a negative diagnosis is arrived at. The presence of Epe in a smear need not necessarily imply disease.
  • Serological tests, including an ELISA, are still unreliable but are being improved.
  • Evidence of other causes of anaemia (e.g. iron/copper deficiency).
  • Examination of blood samples for packed cell volume and haemoglobin levels.
Epe must be differentiated from the following:
    - Actinobacillus pleuropneumonia.
    - Chronic respiratory disease complexes with PRRS and influenza.
    - Gl?ssers disease - Haemophilus parasuis.
    - Leptospirosis (L. icterohaemorrhagiae).
    - Malabsorption and chronic enteritis.
    - Pale piglet syndrome - haemorrhages.
    - Porcine enteropathy (PE, NE, PHE and PIA).
    - Post weaning multisystemic wasting syndrome (PMWS)
    - Other causes of anaemia (e.g. Iron / copper deficiency).

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.