A Look Back
As soon as puppies are born, one of the first things they will experience is the warmth of their mother's tongue. When mother dog vigorously licks her puppies right after birth, she is cleaning them up from the afterbirth, but at the same time, she is also stimulating them to breathe.
Licking will continue for some time considering that, when puppies are very young, they are unable to eliminate on their own. Mother dog will have to often lick their bottoms to stimulate them to go potty. This licking will persist during the puppy's first 2 to 3 weeks until they are capable of expelling waste on their own.
Once puppies are starting to be weaned, generally between three and four weeks of age, it's now their turn for starting to lick mother dog. At this age, puppies may start to lick the corner's of mother dog's mouth in hopes of getting her to regurgitate a meal for them.
This behavior is reminiscent of the dog's ancestral past, when a dog's ancestors whelped their puppies in a den. At some point, the puppies needed to transition from milk to meat, and the only way to help this transition was for mother dog to leave the den, consume a meal and then return to the den and regurgitate for her puppies who would greet her by licking the corners of her lips.
This behavior was highly adaptive considering that it was risky for young puppies to leave the den at such a young age. Also, the regurgitated food was warm and easy for the puppies to eat and digest, providing an optimal intermediary meal somewhere in between liquid and solid foods.
Did you know? While nowadays puppies no longer live in dens and breeders help wean puppies by offering them puppy gruel and puppy mush (a mix of soaked kibble water and milk replacer), breeders attest that puppies still instinctively lick mother dog's mouth and mother dogs still regurgitate for their puppies. According to research, more than 60 percent of the breeders had observed regurgitation among their dogs.
A Greeting Behavior
Interestingly, the behavior of licking mother's dog mouth during puppy hood persists early puppy hood and morphs into a greeting behavior directed at other dogs and humans.
Among dogs, sniffing and licking the mouth area provides dogs with information, considering that a dog's mouth area is known to provide identification details. Dogs release pheromones (chemical messages) from several body parts and the dog's lip area happens to be one of them.
Puppies and young dogs in particular lick older dog's chin areas and faces as part of their greeting rituals. While it's true, that, as dogs get older they lick each other less often, in many cases they never give up face licking entirely.
With humans, something similar may take place. Dogs greet their owners enthusiastically, and often part of that greeting ritual includes licking the face area of people. While it is obvious that we are not the dog's parents, in someways dogs, (even when old), perhaps see themselves a bit as being our children.
Of course, not all dogs are created equally. Some dogs may be more on the independent side and reserve face licking to rare occasions, while dogs who are more outgoing and sociable may be more propense to it.
A Matter of Attention
It's difficult to ignore and resist a dog who loves to lick faces. Let's face it: dogs who lick faces melt our hearts, most likely because we interpret them as a show of love and compare them to kisses.
It's not unusual therefore for dog owners to giggle and "ohhh" and "awwww" when dogs give them face licks, and dogs quickly understand that face licking is a great way to garner attention.
So what happens when a behavior that dogs perform naturally is encouraged by dog owners? It puts roots and strengthens making it very likely to repeat.
Smell of Food
On top of greeting, when dogs sniff and lick the mouth area of other dogs and people, they may be gathering information about feedings.
It's as if the dogs sniffing and licking where asking something along the lines of "Howdy, have you found any goodies around here recently?"
Face licking may be particularly prominent among the interactions of dogs with babies and toddlers. Dogs who face lick babies and toddlers often do so because babies and toddlers tend to be messy eaters and the corners of their mouths often house tasty crumbs and food remnants.
A Kiss to Dismiss
Important to point out is that not all dog face licking is created equally; there are face licks and face licks. Particular attention deserves what Certified Dog Behavior Consultant Jennifer Skyrock calls the "kiss to dismiss."
This form of facial licking is actually meant to put some distance and it may be seen in dogs who are not comfortable, and possibly, even anxious about an interaction.
It is also possible that some dogs may lick faces as an alternate displacement behavior to biting. These dogs may have learned that nipping is not an acceptable behavior and therefore replace it with excessive licking. Some professionals refer to this form of licking as a "sublimated bite," in other words, a bite that is so strongly inhibited it morphs into licking with no tooth contact.
Sometimes dogs resort to face licking as a way to get a human or other dog to move away or relinquish something. A dog may therefore lick the face of a toddler if he wants the toy the toddler has or he wants to lay down on the pillow the toddler is laying down on.
Of course, not all dogs are prone to this form of face, but it's worthy of pointing out.
Now That You Know...
Many dog owners may wonder whether face licking is unhygienic and whether dogs can transmit diseases this way. Well, for sure it can't be called hygienic considering that dog tongues are used for mopping crumbs off floors and used a toilet paper when cleaning their privates!
Diseases that are transmitted by dogs to humans are known as zoonotic. There aren't too many that can be transmitted though saliva other than rabies (most dogs are vaccinating fortunately due to rabies law) and Capnocytophaga canimorsus, salmonella and some other bacterial conditions, but most of them occur due to people having lowered immune systems. So here are some tips for owners of dogs prone to face licking.
- Wash your face after your dog licks you. Although saliva-transmitted diseases are not common, it's good practice to play it safe.
- Avoid your dog's face licking if your dog is sick or if your immune system is lowered or you do not have a spleen or you are undergoing chemotherapy. Alcoholics are at greater risk to saliva-transmitted disease due to having less efficient infection-fighting white blood cells.
- If you want your dog to not lick your guest's faces, keep him on a leash or you can train your dog to got to his mat.
- Keep an eye on your dog's body posture and context when he licks your face. Does he look tense? Is he trying to move you away? Evaluate whether you may be dealing with a kiss to dismiss facial lick. If in doubt, consult with a dog behavior professional.