I write about Capnocytophaga canimorsus regularly… disproportionately so, since it’s a rare cause of disease in people. However, though rare, when disease does happen it’s usually serious, and cases illustrate some important basic concepts that apply more broadly to other zoonotic diseases from pets.

The title of this post is from the latest edition of the Canadian Journal of Infectious Diseases and Medical Microbiology, which includes a report describing a single case of Capnocytophaga infection in a person (Popiel et al 2013). In that respect, it’s not particularly remarkable, but some common themes and a few interesting statements that appear are worth considering.

The case report is about a 56-year-old male who presented with fever, headache, joint pain and nausea. He had some other health problems and was a heavy drinker (a major risk factor for Capnocytophaga infection). He developed Capnocytophaga meningitis and deteriorated quickly, but fortunately responded to treatment. The family dog had bitten the man on a finger a week earlier. As is common, it was a minor bite and one that was likely dismissed as inconsequential. However, a minor bite is all that’s needed to drive Capnocytophaga into the body.

The paper starts with the sentence “In 1976, Bobo and Newton (1) described a syndrome that would forever change mankind’s relationships with their canines.

I think that’s completely false. I’d wager that >99.99% of people have never heard of this bacterium. Most veterinarians haven’t either, and I suspect the same could be said about most physicians. So, I don’t see how it could have had a major impact on how people interact with dogs.

In some ways, I’d like this statement to be true, if it meant that people paid more attention to zoonotic diseases and improved basic disease prevention practices (e.g. hand hygiene, having high risk individuals avoid contact with saliva, good bite prevention and bite care). In other ways, I’m glad it’s not true, were it to result in people being paranoid of this bacterium (that’s found in the mouth of pretty much every dog) and limiting the positive aspects of pet ownership and contact.

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