Every year or so, there’s a new wave of publicity/paranoia about the risks associated with dogs licking people. Often, it follows a study of bacteria that can be found in the mouths of dogs. It leads to a combination of balanced reports, sensational reports and defensive responses.

What is the concern?

Dog’s mouths are vats of billions of bacteria from thousands of different species. Some of those species can cause disease in people. Licking can be an effective way to transfer some of these bacteria to people.

What is the real risk?

That’s the tough question. Dogs lick people all the time. Very few people get sick. Every dog has something in its mouth that could kill a person in the right situation. The same could be said of every person’s mouth (as well as lots of door knobs and other surfaces we touch all the time). We get exposed to disease-causing bacteria incredibly often… probably multiple times a day at least.

The overall risk of disease from a dog lick is low, but there is some risk and it’s wise not to ignore it.

Risk reduction is the key.

Are some situations riskier than others?

Yes. The implications of exposure to bacteria in dog saliva are higher in some groups, namely:

  • People who have compromised immune systems
  • People who don’t have a spleen (that’s related to immunocompromise but is a noteworthy group because of the risk posed by the bacterium Capnocytophaga canimorsus)
  • The very young (less than 5 years of age) and elderly
  • Pregnant women

Some situations pose additional increased risk

  • Licking broken skin
  • Licking mucous membranes (e.g. mouth, nose, eyes)
  • Licking around invasive devices (e.g. people with an indwelling catheter)
  • Licking around the ears (especially in young kids)

What about the dog?

People aren’t the only ones who are exposed to bacteria when a dog licks them. Dogs can pick up bacteria from the person. We’ve previously shown that being allowed to lick people is a risk factor for hospital visitation dogs acquiring MRSA (methicillin-resistant Staphylococcus aureus).

What’s the take home message?

  • High risk people should not be licked by dogs.
  • Dogs that are sick, eat raw meat, or have risk factors for carrying resistant bacteria increase the risk.

The basic themes apply to more than licking, but to a variety of diseases and potential exposures.  High-risk people need to know they are high-risk, and they need to take some extra precautions; low-risk people need to think about the cost/benefit as well. If you’re low-risk and you like dogs licking you, go for it if you feel it’s worth the experience. If you don’t like it, why take the risk?

The risk dog slobber poses to the average person is quite low. Personally, I don’t like my dog licking me. That being said, if he catches me by surprise and licks me, I don’t run screaming from the room and douse myself with disinfectant.