Your dog might offer up kisses for a few reasons.
You taste good
Our sweaty, salty skin can be intriguing to dogs, who tend to explore the world with their mouths and are comforted by the scent of their caring owners. It’s the same reason they often steal our socks and underwear. This, combined with the resulting attention and endorphins described below, makes smooches both tasty and rewarding for our pets.
A genetic trait
According to noted dog behavior expert, Victoria Stillwell, “right from birth, the mother communicates with her new puppies by licking them, it’s how she stimulates them to start breathing and how she cleans them when they are born, so it’s very important to the survival of puppies. In the wild and in domestic dogs, you’ll find they will lick around the mother’s mouth as newborns and puppies still retain that instinct. It’s also a submissive gesture — the more subordinate members of a pack will lick the more dominant members and that’s important in maintaining pack harmony.
It’s an enjoyable experience
Licking releases pleasurable endorphins which gives dogs a feeling of comfort and pleasure — like the feeling people get when they are biting their nails — it relieves stress.
You “reward” your dog
Think back to the last time your dog licked you and how you responded? Did you reach down and give him a scratch? Offer him food? Say something to him (even if it’s something like, “Stop licking me, would you?!”)? All of these actions are forms of positive reinforcement—showing your dog that licking you will get some form of attention, thereby encouraging him to continue the behavior in the future.
If your dog’s licking is purely a sign of affection, one way to decrease this is to ignore the licking. Licking never gets attention. If your dog licks you, then you immediately stand up and walk into another room. You want to teach your dog that licking means the person will leave the room. The same thing applies when you’re petting your dog if he starts to lick, the petting stops, and you walk away. With repetition, the licking will stop.
To show submission
Your dog might be licking to show submission, especially if he’s licking another dog’s muzzle. According to former AKC Family Dog columnist and veterinarian Nicholas Dodman, wild puppies lick their mother’s mouth as a signal for her to regurgitate the meat she’s hunted and as a way of demonstrating subordination. It makes sense, that domesticated dogs use this instinctual behavior when interacting with other dogs (or humans) they consider superior to them.
A possible medical (or behavior) issue
Dogs that repeatedly lick a certain spot might be suffering from an issue that needs a specialist’s intervention, including anxiety or obsessive-compulsive disorder. Also, dogs who frequently lick their feet may be trying to resolve a persistent itch caused by allergies. Dogs who lick their anal area frequently could be suffering from allergies or may need their anal glands expressed. If you notice your dog obsessively licking themselves, a person, or an object (bed sheets, for example), speak with a veterinarian, who may recommend medical treatment or a consultation with a behavior specialist.
If a dog is chronically licking himself, it can be because he is bored, anxious, has skin problems such as allergies, or could be feeling pain either in their paws or elsewhere in their bodies. You should make sure your dog is getting enough stimulation and rule out any infections or allergies by visiting your vet.
Our thanks to the following organizations for this information: