Renal abscess with Capnocytophaga canimorsus infection from a dog bite.

We present a case of renal abscess caused by Capnocytophaga canimorsus infection in a previously healthy middle-aged man. He presented with sepsis and an acute kidney injury, and although not identified on his initial assessment, he had sustained a dog bite 5 days prior to hospital admission. The patient developed left loin pain and imaging investigation revealed a renal abscess. Gram stain showed a gram-negative bacillus and C. canimorsus was identified by 16S PCR from these samples along with aspirate from the abscess. The patient responded to treatment with carbapenems but required a prolonged course. His clinical condition was further complicated by a pleural effusion and the development of fatigue symptoms consistent with a post-infection chronic fatigue syndrome. We present this case which we believe to be the first documented case of C. canimorsus causing renal abscess. We discuss the challenges relating to investigation, management and the importance of detailed diagnostic exposure histories in sepsis of unknown origin.