I have a pit bull that had a similiar problem. This is potentially a very serious problem that is causing a lot of pain. GO TO THE VET. Because these dogs are very tough dogs, they do not let on that they are in a lot of pain. Our dog developed a limp. Little did I know her joints did not develope properly and her knees and legs kept slipping out of their sockets. She has had 3 surgeries and unfortunately will need more. I would suggest seeing a specialist for any surgeries. It will cost more, but save you unneccissary procedures.