Granulocytic anaplasmosis in a horse from Nova Scotia caused by infection with Anaplasma phagocytophilum

A 16-year-old Paint stallion was presented with intermittent fever, inappetance, lethargy, icterus, distal limb edema, and submandibular lymphadenopathy. The horse was native to Nova Scotia and had never left that province. Morulae were detected in granulocytes. Anaplasma phagocytophilum infection was confirmed by serology and polymerase chain reaction (PCR). The horse responded to treatment with oxytetracycline.