Anyone who has ever played with a dog knows that these interactions can range from you gingerly tapping the dog on the top of the head with one finger while trying to keep out of range of the dog's tongue; to working your hands through the dog's hair while the dog gratefully licks at your hand in the throes of the massage; to your needing a shower after being slobbered all over with doggie saliva. Why is it that dogs feel the need to lick us–and even their own selves?
From the moment of birth, the first thing a mother does to her puppies is lick them. Those of us old enough can remember the days when a doctor would hold a newborn child upside down by the ankles and deliver a whack on the buttocks to stimulate the baby to open the mouth to cry and thus start breathing. Mother dogs stimulate their newborn puppies to breathe by licking them–this also assures the mum that they are alive and not stillborn. This is how she cleans the puppy and she will eat the afterbirth which provides much-needed nutrition as well as a sanitary den environment. Licking stimulates urination and defecation in the puppies. This is the first form of communication and social interaction a puppy receives and as we'll see later on, dogs continue to use licking as a form of communication.
As the puppies get bigger the mother starts to wean them off her milk and on to solid food. She usually leaves them in the safety of the den and goes out to hunt, or food is brought to her by her mate. When she eats this food and returns to the den she has to get the food from her tummy into the tummies of her young. She is stimulated to regurgitate the partially digested food by being licked around the muzzle by her puppies. This is why dogs lick us on our faces: they retain this behavioural trait which is how they obtained food from their mothers.
The puppies continue to grow into adults and licking serves to welcome other members back into the pack after a hunt or territorial patrol, to strengthen the bonds between pack or family members, and as a sign of deference or submissiveness to a dominant pack member. You will notice that the submissive dog lowers the body to the ground and licks up at the dominant dog while the dominant dog stands to accept the licking but does not necessarily return the favour. This gesture is important in maintaining pack harmony, and dogs within our homes continue to lick their owners as a sign of submission and to strengthen the human-animal bond.
Licking is also used for grooming, keeping clean, and treating open wounds. You may have observed that your dog goes outside to play, gets mud all over the paws and "bathes" by licking the mud off or even pulls at and removes twigs, grasses or other vegetation caught in the dog's hair coat. There were no vets in the wild thus self-medication was necessary in the ancestors of the dog. The saliva of canines contains enzymes that kill bacteria, so licking helps to get rid of dead tissue, clean dirt from open wounds, and accelerate the healing process. Be cautious with dogs who lick themselves excessively after surgery–in such instances licking may re-open wounds and actually retard healing so you should ensure that these dogs wear a protective Elizabethan-collar during the recovery period.
Licking can become compulsive–you can distinguish this behaviour from normal licking because the dog licks the same area or object excessively and seems to be doing so during times of stress, anxiety, frustration, or boredom. You should seek professional advice from a behaviourist to treat this habit because the dog can develop accral lick dermatitis and may even engage in self-mutilation. Rule out any licking due to skin problems, allergies, or infections by visiting your veterinarian.
As we have covered in a previous article–dogs have taste buds. This is why they continue to lick their bowls after a tasty meal, why they lick up spills in the kitchen, and they may lick us because we taste good! They may enjoy the salt on our skins, and some of us (especially young children) may have food particles on our bodies if we are messy eaters.
Licking as a form of communication is varied. There are several messages our dog is relaying to us but not many of us are versed in this canine language. "Dog-speak" can mean: "You're back home–I've missed you and am happy to see you;" "Did you bring home any treats?" "I'm hungry;" "What's wrong–why are you sad?" "Come and see what I've caught in my latest hunting expedition!" "You're mine–I'm marking you with my scent;" "Why are you ignoring me–I want your attention;" and the three greatest–"I am sorry;" "I forgive you;" and "I love you."
The most common reason for licking is affection. Licking for affection causes your dog to release pleasurable endorphins that calm and comfort them, so try accepting these k-9 kisses graciously –you can always wash afterwards!