thank you guys I need to make an appointment to take him to the vet. I kept him away from walking this whole weekend. he decided to sprint on his own and was fine. This morning I wanted to take him for a light walk just to poop and since we use a harness he tried to pulle several times but I corrected him so on the way home he had a weird motion on his back leg. He doesn't limp but he has that ghetto limp you see with the hoodlums? lol it's not funny but that is the best way I can describe. I think it was my fault to push him so much even though he was leaner and wanting to work more. I pray that it's a pulled muscle or something muinor, I don't care if I dont ever get to work him I just don't want to loose my boy :( not again...