I think that spanking your dog is wrong and has no affect on the dog whatsoever! I have a female Jack Russell. She was posted in the newspaper by a family that didn't have enough time for her. When we arrived to see her she immediately came running to me and it was love at first sight. The owner then proceeded to inform me that the people she had purchased her from had thrown her down a flight of stairs when she was just a pup and her leg was broke. They didn't take her to the vet to have it checked so she now has a permanent limp and if she runs too much it caused her pain. When she told me this I was mortified!
How could someone think that throwing a puppy down the stairs would possiblly teach her anything besides to fear humans?! She is very timid and if she does something she knows she is not supposed to and is spoke to in even the slightest harsh manner she falls onto her back and pees all over herself. Had she not been treated this way she would not have these concerns! We never spank her. MAinly because it is just wrong but we wouldn't even have to she is very smart and knows what she can and can't do. When she knows we are mad at her she apologizes in such a sweet way you can't be mad at her.