Excessive licking can happen three ways: your dog can excessively lick humans, lick him/herself or lick objects. There are different ways to deal with each one--and I'll tell you how in this article.
Some dogs excessively lick their owners or guests. This can become very annoying. Dogs tend to lick humans because they are nervous or have been unintentionally rewarded for doing it. When your dog starts to lick you or a guest, firmly give the command "Stop" and quickly pull away. The second your dog stops licking, give your dog a favorite toy. You are redirecting the behavior and giving your dog something else to do with his mouth.
If your dog excessively licks objects you can use a taste deterrent. A taste deterrent is anything that your dog does not like the taste of. Hot sauce and hot mustard are good deterrents. There are also commercial taste deterrents you can purchase at a pet supply store like bitter apple and sour grapes. By putting the taste deterrent on the objects your dog likes to lick, you can stop this behavior. It's important that you give your dog something to chew on like a stuffed Kong toy or Nylabone in place of the off-limits object.
Dogs will lick themselves for two reasons: behavior or physical. Some dogs will lick excessively when they are stressed. A dog with this type of behavior problem will only be helped when you uncover the underlying reason for the behavior. What is the dog stressed or nervous about? Once you find out the underlying reason and deal with it, the behavior should go away. Dogs with physical problems will also lick excessively. It could be related to food such as a poor diet or allergy to one of the ingredients. Check the ingredients.
Check to see if there are any other irritants that may be causing the licking. Some dogs will develop problems during the winter or spring due to salt or lawn treatments.