Many people think of affectionate licks from their dogs as doggie kisses, while others recoil at the sensation. Experts have several theories, positive and negative, about what makes dogs lick.
Puppies learn to lick from their mothers, who lick them to clean them and encourage digestion. Licking also helps bond a mother dog to her pups, according to animal behaviorist Nicholas Dodman at Pet Place.
Sometimes dogs lick to express affection toward someone they respect, such as a human owner. Animal Planet dog trainer Victoria Stilwell states that dogs also like the salty taste of their humans' skin.
Other times, licking is a naughty behavior for a dog. Some dogs, who like being the center of attention, lick their humans to express dominance. Dodman states that they notice that it makes humans more animated, either because they like it, or they start shooing the dog away.
Humans may unintentionally train their dogs to lick by rewarding the behavior with affection, according to Dodman. In other words, when dogs lick, humans, thinking that licks are kisses, pet the dog, which the dog interprets as a reward.