I have a 6 month old male rottie named Zeus. He has been growing at an exceptional rate the past few months. Im talking 30 pounds in a little over a month. And in the past few weeks he has began to favor his left leg limping and sometimes he will pull his foot up. What are the chances of this being hip dysplacia? I got him from a very good breeder with guarantees on hips and everything. If not hip dysplacia, what else could be causing this? Are there any recomendations of vitamins or anything to help with his muscle bone and joint formation? Any response would be good Im worried about him!