There are a number of reasons your dog might lick all the time. From a habit formed after an injury to a desire for your love and attention, a constantly licking dog can get on your nerves as an owner. Constant licking could also create raw spots on your dog's skin that could lead to infection and scarring. There are a number of different things you can do to stop your dog from licking all the time.
Entertain your dog with a nice, long walk. One of the major causes of excessive licking is boredom and lack of exercise. Playing with and walking your dog regularly will ensure that she doesn't get too bored and start licking to entertain herself.
Divert the behaviour by turning away from your dog if he licks you in an overexcited manner upon returning home. In time, he will catch on that this is not acceptable. You will also want to share this tip with guests so your dog doesn't jump up and lick them upon arrival.
Spray the surface of your skin, your dog's skin, the floor or whatever it is your dog is licking obsessively with a natural, nontoxic deterrent, like sour apple spray. If your dog tastes something bad when she's licking, it will force her to stop the behaviour. You can find many brands of sour apple spray in your local pet store and in online shops.
Put a cone collar on your dog before bed and before leaving for work in the morning to keep your dog from licking while you're not there to correct him.
Teach your dog a few tricks that will supplement her desire for attention and praise. By showing her how to shake hands or roll over, your participation in the trick will give your dog the positive attention she craves.
Redirecting the negative behaviour to a more positive behaviour is necessary when training your dog to stop licking.