[jakesfostermom]

Legend - you surely have some leadership/respect issues to deal with here - and sooner rather than later - but since you noted he was in pain recently, I'd think you should have him checked over by your vet too. You posted that he was limping previously, right? Is he possibly still in some pain? (I need to finish reading your posts).

Have you talked to his "good breeder" about this behavior of his? A good breeder will have trainer recommendations for you - as well as any insight into temperament concerns in his lines. They'd be first on my list to contact!

I also agree with Zorro on finding a more experienced trainer than those you find at Petsmart......Petsmart is a decent starting point for puppies, but you've got a budding adolescent male on your hands and both of you need some serious professional guidance before he hurts someone. I also agree on the dog park concern.......dog parks are NO place for dogs with ANY issues - particularly a dog showing signs of aggression to people, when simply being expected to do something he doesn't want to do.

I hope you'll get serious and get on the phone to find a qualified trainer in your area - someone who is experienced with large breeds, someone who is comfortable working with a dog who might be a bit edgy at receiving 'direction' initially. Good luck - he needs to be knocked down a peg or two or four - to the bottom - but without help and/or done improperly, this process could get you bitten!