My two-year-old Boxer-Pit mix has a limp with her back right leg. She has fallen on the snow this winter and we don't know if she injured it by falling, or if the lameness caused the fall. The limp is not always apparent and there seems to be little if any pain associated with touch. Is hip dysplasia common in these dogs? How can I learn what is the cause of the limp and what can I do short of surgery if it is dysplasia?