Chihuahua holding toothbrush in mouth

Man's best friend has better oral hygiene than man himself, if the old saying is to be believed. But are dog germs and human germs even comparable?

It’s an old saying you’ve likely heard many times before: a dog’s mouth is cleaner than a human’s mouth. Of course, usually you hear it from people who’ve just let their dog lick them all over the face or even ... inside their mouths. Where would someone get the idea that a dog has a cleaner mouth than a person? Some say it's based on dogs licking their own wounds and how they seemingly heal up faster, or how human bites can actually be worse than dog bites. While the legend's origin may remain a mystery, the facts are not: you really don't want your dog's germs getting inside your mouth.

Dog Germs vs Human Germs

Yes, it is a myth, but whether or not a dog’s mouth is cleaner than a human’s mouth can be tricky to prove. Although everyone's mouth is going to be unique, Fido’s kisser may indeed have fewer germs than yours, as far as numbers go. But the more critical bit of information is the type of germs in a canine’s mouth as opposed to the germs floating around your own. In other words, it’s more a matter of germ quality versus germ quantity. There are human germs and there are dog germs, and they can be two very different things.

Everyone already knows how much bacteria we humans can carry around on our hands. Everything we touch throughout a day - handrails, bathroom door handles, cell phones, TV remotes, etc. - are virtual germ hotbeds. Now compare the cleanliness of the average human’s hands with what is essentially a dog’s hands: its mouth. Your dog is licking, taste testing, gnawing on, or just straight up eating nearly everything in its path throughout his or her life (and anyone who also owns a cat and has a litter box in the house knows what that means). Now just imagine yourself doing the same thing. Not a pretty picture, right?

Dog's Mouth vs Human Mouth

Oral hygiene also plays a role as well, since a healthy mouth is generally associated with a clean mouth. With that in mind, the better you take care of your (and your dog’s) teeth and gums the healthier both of your mouths will be. But when you take into account what your dog uses its mouth and tongue for throughout a given day, it’s probably best to skip the open mouth kisses and stick with a good ear scratching or belly rub to express your affection, instead.