Our cockapoo understands that when visitors arrive at our house he is not allowed to jump up on them because he has been trained. In the park when he is off the lead however it is a different matter. He knows that people usually carry treats and is very persistent and can jump up fairly high! I did ask months ago when he was at puppy class what to do about this and was told that as most people either pat a dog or give them treats it was very hard to control and that he would grow out of it. I have been told in our local park that someone is going to clock me very soon and to train my dog!! He is 8 months old. Any advice pleeeeeease.