We have this wheaten at work, about a year old. Over the past few months we've noticed that after a hard round of playing, or especially during a boarding stay, he limps. He just went home today after a week-long stay and was very subued for the last three or four days, not playing and bunny hopping, or at least skipping, on his hind end. He does spend endless amounts of time pogo jumping in his room, which probably doesn't help. But when I told him mom about it, she said she had just gotten his hips checked last month when they did the neuter and the vet said they looked fine. I suggested she send the x-rays off for a second opinion at either OFA or PennHIP, or have the vet check the knees. I think he walks like he has the early stages of hip dysplasia, but it's not constant and apparently doesn't show on x-rays. Any other ideas what it could be? He is a pet-store puppy that sells out of standard and HD-prone wheaties, which is why I'm thinking HD.