Why do Dogs Lick?
Dogs use a variety of ways to show their owners affection. Jumping up and down after being separated for a while, snuggling at the end of the day, and giving wet doggy kisses are all things that many dog owners enjoy. But where does the habit of licking people come from?
We don’t lick our dogs, so how does this seemingly universal habit develop?
Why do Dogs Lick? – Grown From a Mother’s Love

Once the puppy grows up, the habit continues. A dog will lick other dogs for the same reasons he licked his mother when he was a puppy– it’s a sign of affection and shows submission to the “alpha” dog in the pack (or in most cases, the “alpha” dog of the household). But many people wind up being the recipients of these doggy kisses.
It makes sense when you think about it. As your dog’s primary caregiver, you fulfill the role that was once held by your dog’s mother. You feed him, groom him, show him affection, make sure that his needs are taken care of, and protect him from harm.
In doing so, you essentially become both a sort of alpha dog and parent to your pup. Your dog appreciates you possibly even more than you appreciate him, so of course he wants to show you how he feels! But, there is more to it than that.
Why do Dogs Lick? – Using Multiple Senses to Communicate

This helps them determine whether a new dog, person, or animal is trustworthy. Once deemed safe, a dog may lick their owner’s friends and family as a gesture of approval. Of course, sometimes the reason a dog licks someone is simply because they taste good– they may have remnants of their last meal on their hands or still smell like it.
On the other hand, when someone has been exercising or sweating, a dog may lick him or her because they like the salty taste on the person’s skin. Since dogs don’t sweat, they most likely don’t realize how odd this seems to us.
Why do Dogs Lick? – Expressing Their Needs

Just think of how children will be extra sweet to their parents when they want something. Dogs do the same thing; they show affection in hopes that they will get what they want as a reward.
However, this can sometimes be used as a means to show concern. If a dog is scared or anxious, he may lick his owner for a few reasons. He may be looking for comfort in the form of a treat or petting, or he may want you to investigate the cause of his distress.
Discouraging The Practice
Some people don’t enjoy doggy kisses or have dogs that lick excessively, but can’t figure out how to make their dogs stop. The trouble is, these pet owners may not realize that they are unintentionally encouraging their dogs to continue the habit.
When a dog performs a certain behavior and is then rewarded, he will eventually learn that he should do that action to get the reward. So while it may seem like scratching your dog behind his ear or petting him to make him leave you alone is making him stop licking, in reality it is actually encouraging him to keep doing it.
In order to discourage your dog from licking you and/or others, you have to be sure not to reward him when he licks. For some dogs, this may be as simple as walking away when he begins to lick you. He will quickly figure out that this behavior makes you leave– something he doesn’t want– so he will stop.
If you have multiple people in the home, it could be necessary to get everyone to react this way when your dog licks them in order to curb the behavior. Having one or more people reward him for licking while everyone else ignores him could negate any efforts to make him stop.
