Even with careful supervision, mistakes are going to happen. The best thing you can do is be calm and be prepared. If you catch the dog in the act, do not freak out and scream obscenities at him. Do not chase him down and whack him with a rolled up newspaper, and do not rub his nose in it. These barbaric methods only teach the dog to fear you and avoid going to the bathroom when you are around. You need to be there to praise him when he eliminates in the right place. While your dog is making a mistake, calmly walk over to him and firmly say “No!” Show disappointment in your facial expression and in the tone of your voice. Then immediately take the dog to the yard or the paper. If you have a smaller dog you can usually stop the mistake in progress by picking him up. He will most likely continue to go when you take him to the correct area as long as you have not made him too nervous. If he continues in the right spot, act totally forgiving and praise the dog. This action constitutes an effective correction: You will have shown him the clear contrast between acceptable and unacceptable behavior. The same results can be achieved with a larger dog by briskly walking him to the area.
If you are unable to catch the dog in the act, your only recourse is to clean up the mess. Always wipe the area down with an odor neutralizer so he will not be attracted to that same spot. Do your best to prevent any mistakes. You cannot correct the dog after the fact; he will not understand what he is being corrected for. Take a deep breath, think happy thoughts and concentrate on how to reward him for going in the right place. Remember: Your dog is not out to get you, and he is not purposely trying to upset you. He would much rather see you happy with him than have you scold him. So concentrate all your efforts into complimenting his successes rather that criticizing his failures. This will guarantee faster results!!!