Sudden and unexpected nontraumatic death in individuals with asplenia or 
hyposplenia is usually due to fulminant bacterial sepsis, most often involving 
Streptococcus pneumoniae, Neisseria meningitidis, and Hemophilus influenzae. We 
report a case of a previously well 40-year-old man who died 5 hours after 
hospital admission. At autopsy Waterhouse-Friderichsen syndrome was identified 
and Capnocytophaga canimorsus was subsequently isolated on antemortem blood 
cultures. Infection of humans with this organism is most often due to dog bite 
or contact. Upon specific inquiry it was ascertained that 2 days before 
admission the deceased had suffered a superficial bite to his hand by his pet 
Staffordshire Bullterrier dog. His relevant history included a previous 
splenectomy following blunt abdominal trauma. Asplenia and hyposplenia at 
autopsy should prompt microbiological testing with consideration of unusual 
organisms such as C. canimorsus. Although histories of animal contact or injury 
are often not available at the time of autopsy, this should also be considered 
in cases of apparent fulminant sepsis. In individuals with asplenia or 
hyposplenia, dog bites do not have to involve excessive tissue trauma, vascular 
compromise, or blood loss to be lethal.