Animal-loving grandmother died from rare infection after her pet dog licked her hand and bacteria spread into her bloodstream.” For me, the first thing I think of when I hear that is Capnocytophaga canimorsus (to which most people respond “Capno-whata cani-whatsis?”).

It’s a tragic but textbook example of what this common dog-associated bacterium rarely can do.  In this case, 53-year-old Sheena Kavanagh developed septic shock from C. canimorsus infection, presumably after the bacterium got into her body when she was licked by her dog.

This bacterium is found in the mouth of virtually all dogs, but rarely causes human infections. The right set of circumstances are required: First, the bacterium has to make it past the body’s skin defenses (usually, it’s via a bite but in this case, the victim had a small cut on her hand and the thought is that saliva got into the cut), and then it has to evade the body’s immune system. Classically, the disease is primarily found in individuals who don’t’ have a functioning spleen (an organ that plays a key role in eliminating some microorganisms from the blood), and that was the case here. As is common, the woman’s condition deteriorated very rapidly, and she died before anyone knew what was happening.

People shouldn’t fear their dogs and become germaphobes. However, people need to be aware of the risks, know some basic preventive measures and know when they are at increased risk of infection. Too often, people who are at increased risk because they have lost their spleen, have an immunocompromising disorder or have some other problem don’t know anything about this and similar issues. Communication with (and between) physicians and veterinarians about these risks is often rare to non-existent.

People like to talk about "one medicine," but we need to actually practice it more often.

More information about Capnocytophaga can be found on the Worms & Germs Resources – Pets page.