Dog licking is universally understood as an affectionate gesture. Dogs lick as a form of communication and to display affection. Dogs also lick to clean themselves or treat wounded areas and dog saliva is recognized as having healing ability for cuts, inhibiting the growth of some forms of bacteria. To humans, a lick from a dog is not always a pleasant experience. Dogs can lick unhygienic areas before using the same tongue in an act they perceive as affectionate. This is one of the reasons constant licking can become an irritation for the dog's owner.
Instructions
Instill a sense of discipline and obedience in the dog. If a dog adopts an obedient and upbeat attitude they will be more pleasant to be around, as well as making it easier to train the dog to behave in a desired manner. The dog must learn from an early age that it is admonished for undesired behavior and rewarded for good behavior by his owner. If a dog is not already instilled with basic discipline to follow commands such as "sit down" or does not have a sense of right and wrong behavior, it will be more difficult to stop the dog from licking his owner.
Be consistent with your demands to not be licked. If you absentmindedly allow the dog to lick you, he will be confused if he is suddenly asked to stop for no apparent reason. When a dog licks you should begin by verbally admonishing him in a reasonable volume using a harsh and stern tone. If this is unsuccessful you can use physical restraint such as pulling the dog away by the collar and ordering him to sit or be still and stop licking. The dog should then be rewarded with positive reinforcement--either a treat, a toy or petting. It is helpful to use a simple command such as "stop it" that the dog begins to recognize as a command to stop a dog licking his owner.
Remember that the dog perceives licking as an act of affection and compassion. It is important to not be too stern with the dog when he licks. If this act is met with an overly harsh response, it could result in the dog feeling helpless and you may lose the love and trust of the dog. Also, the dog may become upset and lick further in an attempt to apologize to his owner rather than stop licking.