Licking the paws is a natural behavior in dogs, it is how they groom and clean their paws. Chances are good your pup spends at least some part of each day grooming himself; this is quite normal. But, when he spends hour after hour licking his paws until they are raw and bleeding, it's time for you to step in and do something as this type behavior is definitely NOT acceptable.
One of the biggest reasons your dog continues to lick and chew on his paws may be his diet. In nature, your dog's diet would consist of mostly meat. A domesticated dog's diet is more grains, fillers, and other miscellaneous, less than healthy, ingredients. Instead of keeping his body in balance, these foods allow yeasts to go crazy, causing significant itching, especially on his paws, which of course he will lick and chew on to try to get relief.
Unlike what you may think, your dog licking his paws should never be looked at as a bad habit or just your pup being bored. Instead should be looked at as a systemic issue. One that may be able to be corrected with a change in his diet. By changing your pup's diet to one that is meat based may help to restore balance to his immune system, which in turn may help reduce his desire to lick his paws.
Pay close attention to the foods your dog eats and at the same time, pay close attention to the condition of his feet. If the fur is pink and his paws look damaged, you should take him to see his vet to make sure the injuries are not severe and to get any medical treatment he may need for his paws to heal.
Start by observing how often and how long your pup spends licking his paws every day for a few days. This will help you to establish the fact he has a paw licking issue. Check each foot for any signs of injury or damage and take him to his vet if you find any. Avoid crazy home remedies such as putting cayenne pepper on his paws (this stuff can really hurt him), or putting vinegar or anything else that tastes nasty on his paws. These things can make your dog very sick. You will need a few things to help with the training, including:
The biggest part of training your dog to stop licking his paws is to be patient and keep working with him until he stops constantly licking. Remember, some licking is a normal part of your pup's normal grooming routine.