Humans often think of canine licking as being nothing more or less than a sign of love and adoration. Although it sometimes is, indeed, a tender gesture, the behavior also often goes a little deeper than that, both in sprightly young puppies and in wise adult pooches. Face licking frequently denotes feelings of subordination.
When a young puppy senses that another dog is a lot stronger, and higher up socially, than he is, he might respond by trying to behave in a humble manner. Remember, dogs naturally live in pack societies that are centered around the power of alpha dogs. Your wee puppy is aware of the dominance of the other dog, who usually is older. If your puppy keeps licking your other dog's face, it's probably because he knows that your other pet has seniority and, therefore, is the "top dog" in your home. By licking his face, he's trying to establish a harmonious and pleasant rapport with him, communicating that he has no desire to dispute his status.
If your puppy has a penchant for licking your other dog on the face, it could be a sign of positive and amiable feelings between them, as long as the other dog does it in return. If your other dog has taken your pup under his wing, and they've both bonded and connected in the time Junior has been in your residence, face licking could be totally unrelated to submission and dominance. It actually could be a sign of caring and confidence between the furry twosome -- aww, It doesn't get much sweeter than that.
Presence of a Wound
Never make any assumptions regarding what your pets might be doing until you take a closer look. If your puppy is licking your other dog's face a lot, it might indicate the presence of a wound, rather than submission or companionship. If that's the case, your other dog might require prompt veterinary assistance, so don't ignore it. Always consult an experienced veterinarian regarding the health and treatment of your pet.
Licking Peoples' Faces, Too
Puppies and mature dogs don't limit their face licking just to fellow canines. They also frequently do it to humans they perceive to be dominant over them, such as their owners. When young puppies lick their owners' faces, it sometimes even is a way to get attention to ask for food or tasty treats.
Puppies in the Wild
Puppies out in nature also lick their mothers' faces to trigger them to regurgitate food -- in soft gruel form. Not only do their mothers regurgitate sustenance for them, so do senior members of the pack. Puppies do this until they're ready to start eating solids.