Whoever told you that was not only wrong, but hurtful, too. All dogs should be trained, in a loving and kind way. Being trained actually makes a happier dog, because the dog now knows what is the right thing to do, and how to make the owner happy! EVERY dog should be trained, the most miserable dogs I have seen were ones with no training. In many breeds, there is a need to be a "working" dog, so training also lets these dogs know what their "job" is! Love and praise and treats help make training both useful and fun!