Oh.. now I understand. Max growls when hes playing? Well that's fairly normal. The growling is mainly just a dog's way of saying 'cmon lets play!' or even trying to provoke a mock-fight. You have to not only listen to your dog, but read his body language. If he is in a play position, with tail high and wagging he probably isn't being very vicious . When our border boys 'wrestle', they roll around and growl a lot! Most passerbys would think it was a dog fight, but they're just playing around and would never agressively nip or bite eachother.

If Max is also starting to mouthe your hands or nip when he plays, you can correct this by ending the play session, like you have done. Tell him 'NO', completely ignore him, even if he is play-growling... and make it clear that that threatens you. You can also try spraying him with water from a spray bottle when he growls at our mouthes you or other people. This alarms him a little, and stops him from doing what he is doing. Maybe you can try using booda bones or other tugs to create a play activity where its okay to be rowdy and play-growl a little. What you're explaining doesn't sound like agression to me at all - but you know your dog better than I do. All I can say is that you should definately go to obedience classes, even if you already have. Take a refresher course so that you can learn to establish your leadership over Max. And try NILIF-ing him like Clara said I'm sure you two will be fine. Maximus is adorable, and sounds like a sweet boy.