Capnocytophaga canimorsus from Dog Saliva Exposure Causing Severe Sepsis in a Healthy Adult: A Case Report

BACKGROUND Capnocytophaga canimorsus is a gram-negative bacterium commonly found in the saliva of dogs and cats. It has the ability to evade the human immune system and cause life-threatening infections, particularly in immunocompromised individuals. C. canimorsus infection was first described in 1976, and additional cases have since been reported, with complications varying from mild to severe. This case report highlights the occurrence of a severe C. canimorsus infection in an immunocompetent patient, which rapidly progressed to septic shock and multiorgan failure. CASE REPORT We present the case of a 63-year-old man with no significant past medical history who presented with weakness, fatigue, and confusion. Further investigation revealed a wound on his lower right extremity, which had been licked by his dog. The causative pathogen was identified as C. canimorsus through blood culture and mass spectrometry. The patient experienced septic shock with multiorgan failure, including acute renal failure, liver failure, and coagulopathy. Prompt initiation of empirical broad-spectrum antibiotics prior to identification of the source of infection proved to be beneficial, resulting in clinical and symptomatic improvement for the patient. CONCLUSIONS This case emphasizes the severe complications that can arise from C. canimorsus infection in immunocompetent individuals, underscoring the importance of early recognition and treatment in cases of sepsis, particularly in those with potential dog saliva exposure.