My big boy Hank is 10 months old (100lbs last week, not overweight he's quite lanky) his back legs have always looked a little disporportionately long, but hes recently started limping. About a month ago he came in not wanting to put weight on his right front paw, I thought he'd injured it somehow. Then two weeks ago it switched to his left rear leg and now switched to his right. He's been quite a bit less active lately too laying around alot. At first I thought pano, but today while playing I noticed he was bunny hopping a bit and when he read running fast he uses both rear legs together (this is the first I've noticed this) I'm terrified that he might have HD! I plan to have him xrayed soon, both his parents had been xrayed and have excellent hips..... I'm not too familiar with this as my 2 previous gsd didn't have hip issues until they were seniors.