HOW TO TEACH YOUR DOG NOT TO BEG
Make it a house rule never to feed your dog table scraps, especially while you are seated
at the table
  1. Have your dog sit while you prepare his food away from
    the dinner table.
  2. If you need to, simply have him stay in another room.  By
    keeping him isolated while you eat, he may eventually
    associate begging with being sent away.
  3. If you prefer having your dog by your side, put him in a
    "down-stay".  If he rises, respond with a firm "NO"  and
    place him back in the proper position.  Praise and reward
    him for good behavior.
  4. Feed your dog or give him a toy that dispenses treats just
    prior to your meal.  Make sure you do not give it after he
    starts begging, or he will perceive it as a reward.
  5. Be consistent.  Research has shown that if you reward him
    even once, the bad habit will become even harder to break.
Remember, the goal is to train your dog to take food only when it is his mealtime or
when you offer him treats; never when he begs.