Mycoplasma suis

Mycoplasma suis causes anemia and agalactia in swine. Formerly referred as Eperythrozoonosis disease.

Alternative names: Eperythrozoonosis, Eperythrozoonsuis, Mycoplasmasuis, Mycoplasma suis


Mycoplasma suis is a mycoplasma that infects erythrocytes causing anemia. Previously this disease was called Eperythrozoonosis and was thought to be caused by a rickettsia called Eperythrozoon suis adhering to erythrocytes. Thanks to technical advances, this organism has been reclassified as a mycoplasma. Clinical disease is more commonly seen in growing pigs, but can also cause reproductive problems. This organism is capable of crossing the placenta and be responsible for the birth of weak and pale piglets and a high pre-weaning mortality. It is widespread and can be detected in both healthy and diseased animals. 



Acute disease:

  • Anorexia
  • Fever of 40-42 ° C after farrow.
  • Anemia.
  • Increased breathing.
  • Anestrus.
  • Pale skin (jaundice).
  • Agalactia.
  • Abortion.
  • Increased  returns.
  • Reduction of conception rate.
  • Reproductive failure.

Lactating piglets:

  • In severe cases it can cause jaundice.
  • Secondary infections tend to occur.
  • More chronic cases that result in slow growth and pigs that do not thrive.
  • Pigs are pale and anemic.

Nursery and fattening:

  • Anemia.
  • Pale pigs (jaundice).
  • Low or variable growth.
  • Pigs are in bad condition, wasted, hairy.


Causes / Contributing Factors

  • Biting insects
  • Internal parasites.
  • Lice or scabies.
  • Cannibalism / Vices (abnormal behavior).
  • Vaccination of several sows with the same needle.
  • When performing tail docking, teeth clipping and when giving iron injections to the piglets.



The presence of the organism does not confirm the diagnosis. To clarify the relation between Mycoplasma suis and the disease, it is necessary to consider the clinical history and identification of the organism in smears of blood stained with Wright dye. Identification of the organism by PCR. Serological tests have so far been unreliable although improving.



Consider the following treatments and consult your veterinarian:

  • Inject piglets with oxytetracycline.
  • Medicate feed of the sows with tetracycline (OTC, CTC) during 4 weeks, repeat the treatment 4 weeks later.
  • Arsalinic acid in feed at a dose of 85 g/Tm has been described as effective in many countries but it is not licensed to be used in animals intended for human consumption. If available, it’s probably the best choice.
  • The response to other products is poor.
  • Disinfect piglets’ processing equipment.
  • Frequent change of needles for vaccination or injections.

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