Does your dog kiss you?
People tend to feel strongly, one way or the other, on the subject of canine “kisses.” While some folks welcome a lickety-lick on the lips, others throw their hands up in horror — and while some see a canine kiss as a sign of affection, others recoil at the risk of infection.
What is the truth? Is it OK for a dog to lick your mouth, or will it make you ill? Read on to make up your own mind.
There is an urban myth that a dog’s mouth is cleaner than our own. This misconception has arisen largely because the mouths of humans and dogs contain different bugs.
However, when you think about what dogs lick…this puts another perspective on those different bugs.
And this is where the first problem with kisses comes in. That “doggy breath” is caused by a mixture of bacteria, plaque and inflammation. When dogs lick you, they’re transferring those doggy bugs onto your skin or into your mouth.
A study by Japanese scientists found that dog saliva contained bacterial pathogens that could cause periodontal disease in humans. That means gum inflammation that can potentially lead to the loosening and loss of teeth. Worse still, if those bugs get into the bloodstream, they can cause infection in the heart or kidney.
Wait a minute, I hear you say — doesn’t dog saliva have disinfectant properties?
This is something I come across regularly as a veterinarian, when people let their dog lick a wound or a surgical incision. They believe that licking is OK because of the natural disinfectant properties of saliva.
This is something the scientists looked into and came up with and “yes but no” answer. It turns out dog saliva is weakly antiseptic toward E. coli and streptococci but little else. Because the most common skin pathogens are staphylococci, licking is a bad choice, especially as it makes the area moist and therefore a better environment in which bugs may breed.
With regard to the dog kissing you, those weak antiseptic properties certainly are not enough to protect your health.
I’m going to sound like a real killjoy here, but a dog’s mouth and lips can be contaminated with some pretty unpleasant things. Just think of those delightful habits of eating poop and scavenging trash, and it’s little wonder a dog could be carrying infectious agents such as salmonella, campylobacter, giardia or toxocara.
The effects of that slurpy kiss could persist in some very unpleasant ways long after the saliva has dried. And that’s without taking the behavioral side of licking and kissing into account.
Lick That Behavior
Dogs love to lick.
A mother licks her newborn puppies in order to stimulate them to pass urine and feces. A dog licks their paw in order to comfort themselves, just like a child sucks their thumb. Dogs lick to find out about their environment and read scent messages.
This cute pit bull can’t wait to impart some bacteria-laden saliva onto his human’s face:
However, what many people fail to realize is that licking can be a sign of anxiety. The first time your dog licks you, it could be because the dog is worried and is giving you an appeasement signal. Rather than saying, “I love you,” he’s actually saying, “I’m a bit scared of you.”
But licking is habit forming, so when you giggle and give the dog a fuss, he’s likely to repeat the action to get attention. This can lead to unwelcome licking that is intrusive and downright soggy.
To break this habit, say, “No” in a firm voice, get up and walk away. Denying the dog attention when he licks sends out a strong message that it displeases you.
Alternatively, you can put the behavior on cue and teach the dog a “lick” command. This then gives you the means to teach a “No kiss” command when you want licking to stop.
Canine kisses may be cute, but they’re not without hazard. You do risk picking up infections. So why not teach your dog a healthy “high-five” greeting instead?
- Distribution of periodontopathic bacterial species in dogs and their owners. Yamasaki, Nomura et al. Archives of Oral Biology.
- Antibacterial properties of saliva: Role in maternal periparturient grooming and in licking wounds. Hart & Powell. Physiol Behav. Sept 1990: 48 (3).
This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed Feb. 5, 2016.