Capnocytophaga canimorsus bacteraemia demonstrated by a positive peripheral blood smear

The observation of bacteria in a peripheral blood smear was conducive to the diagnosis of Capnocytophaga canimorsus septicaemia in a patient with no definite record of animal bites. Multiple rods were seen extracellularly and within the cytoplasm of neutrophils. The blood culture became positive after 18 h of incubation. Disseminated intravascular coagulation (DIC) was manifest and infarction of the spleen was suspected. Direct examination of peripheral blood smears could be a valuable adjunct in the diagnosis of overwhelming bacteraemia.