# Capnocytophaga canimorsus endocarditis following a dog lick – a case report

## TL;DR

A rare case of heart infection caused by a bacterium from a dog lick highlights the risk of infections from pet contact, especially for those with open wounds.

## Contribution

Reports a novel case of Capnocytophaga canimorsus endocarditis likely caused by a dog lick, not a bite, emphasizing underappreciated infection risks.

## Key findings

- C. canimorsus was confirmed as the cause of endocarditis via blood cultures and genetic sequencing.
- Infection likely occurred from a dog licking an open wound, not a bite.
- Rising pet ownership may contribute to increased C. canimorsus infections.

## Abstract

Capnocytophaga canimorsus is a fastidious Gram-negative bacterium found in the mouths of dogs and cats. It is a rare cause of infective endocarditis, when it is often associated with dog bites. We present a case of C. canimorsus infective endocarditis complicated by aortic regurgitation and root abscess in a patient with a history of previous infective endocarditis. The patient underwent redo aortic valve surgery with aortic valve replacement. Blood cultures and 16S ribosomal ribonucleic acid gene amplification and sequencing from the excised valve tissue confirmed C. canimorsus as the cause. The patient was treated with beta-lactam antibiotics and discharged home. Rather than secondary to a dog bite, infection most likely occurred due to a dog licking an open wound. It is important to remember that dog contact, often perceived as innocuous, such as being licked, can be a source of serious infection, particularly in the context of an open wound. Over a third of households in the UK own a dog as a pet. With C. canimorsus infections thought to be on the rise, in part due to increased pet ownership, there is a need to ensure pet owners, particularly those at risk of infections and chronic skin wounds, are educated on such risks and the appropriate preventative steps.