Many dogs get hot spots…sores on their skin that they constantly lick at…
As mentioned at http://www.canismajor.com, you need to try to determine why your dog is licking. Is it due to grooming, allergies, or is there an underlying behavioral problem?
The following ideas may help to deter them in licking when applied to the sores:
aloe vera (assists in healing as well)
lemon juice (assists in disinfecting as well)
cayenne pepper (a hemostat, helpful in stopping bleeding and closing wounds)
Seek the advice of your vet first.
They may give you a topical bitter spray that may help in discouraging your pup to stop licking. (We tried a bitter apple one with Diojee when she was spayed, but it didn't work on her.)
For non-topical solutions, can try the old standby of an Elizabethan collar (how sad they look with these on), or, better yet, if possible try using a nightshirt or tshirt.