Diagnosis
M. suis is an unlikely cause of major disease. The history, signs and gross lesions often are of value in diagnosis. Confirmation is made by demonstrating the organisms in blood smears stained with Wright-Giemsa or Diff-Quick stains. The organisms are usually found on the surface of erythrocytes and/or in the plasma. Infection with M. suis must be differentiated from other causes of anemia. A careful search for concurrent diseases should be made. Differential diagnoses include systemic salmonellosis, porcine circovirus associated disease (PCVAD), mycotoxicosis, hepatotoxicosis, iron deficiency anemia, or autoimmune hemolytic anemia.