Spaniel tongueI like to write about interesting papers that appear in the medical literature. A problem with that is that it’s often weird cases that get published.  So, it’s important to keep things in perspective.

Regardless, reports of rare things still provide some insight, as long as people don’t over-react (which, unfortunately, is often the case).

A great example of this is a recent case report entitled “An unusual case of meningitis” in the Canadian Journal of Infectious Diseases and Medical Microbiology (Pond et al, 2015).

Here’s the short version:

  • A 56-year-old man with chronic ear discharge and a perforated eardrum was admitted to hospital for ear surgery.
  • Post-operatively, he developed neurological disease and was diagnosed with meningitis. Ultimately, the cause was identified as the bacterium Pasteurella multocida. This bacterium is most commonly associated with the mouth of cats and dogs (particularly cats) and periodically causes infections in people (especially cat bite infections).
  • Finding this bacterium led to investigation of pet contact (ideally, this should be queried routinely, not just in response to a potential pet-associated infection) and it was discovered that the man took care of several cats and a dog.
  • There was no history of a bite (a common source of Pasteurella infection), but the pets were occasionally allowed to lick his face. That’s presumably the route of infection here, although there was no further investigation.
  • The good news is the man recovered.

I get asked about risks associated with licking all the time. My typical response is that I don’t like my dog licking me – it’s not a germaphobic thing, I just don’t particularly like it. The risk to most people is quite low. I do recommend that licking of people at increased risk of infection be avoided. That would include infants, elderly individuals, people with compromised immune systems and people with open sores. I especially recommend avoiding licking around the face, for a few reasons.

The person in this case report would have fallen under the higher-risk group, by virtue of his chronic ear problems and perforated eardrum. Licking around the ear would pose an increased risk of the bacterium accessing the brain through the ear and perforated eardrum. Certainly, it’s a rare problem, but it emphasizes the need for people at increased risk of infection to take additional precautions.

A big challenge is identifying higher-risk individuals and getting them information about what to do and not do. Better communication between veterinarians and physicians, routine questioning of pet contact in human patients, and better access to basic educational materials (like the info sheets we have on the Worms & Germs Resources – Pets page) are important aspects of this.