Cannot play with my 9 month old labrador without him resorting to biting. Even turning my back or walking away doesnt stop it he will just bite at your back or legs, as he hes bigger now its sore. Impossible to have play time with him as it results in this biting, play stops when this happens but we have tried everything to discourage it to no avail. Nothing seems to work. Im afraid he will hurt someone, other than that he is such a pleasant dog with a really good disposition but this has to stop. Any help or advise is appreciated.