Sam is 8 months and hasn't been tested for HD. His parents didn't have it, but I didn't know much about HD since we had poms growing up. Sam did shoot up in size pretty quick so its always in the back of my mind. I picked up some Glucosamine chews the other day, but just thought maybe its too early. He got neutered at 7 months and was 58lbs. But I have cut back a little on his food, and have stepped up the exercise so he doesn't seem much heavier now.