I remember when our old dog, this half miniature schnauzer/half schnauzer, started to get age problems. He was around 13 or so when he finally passed away, I think. He got slower and slower nearly every day in his last few years. When I was little, I used to race him down the stairs in the morning and he would always run by like a gray blur and beat me single pawedly. When I started to catch up to him, I thought I was just getting faster. Then I realized he was getting slower. By the end, he had to slowly walk down one step at a time, wheezing and coughing.
I still remember waking up, and my brother and dad were in the bathroom taking care of him because he hadn't been able to stand up that morning. They had him down on towels down in the bath tub, trying to keep him in one place, using a damp cloth to cool him down and make him relaxed. Panting and wheezing. I went downstairs and waited with my mom for what seemed like ages. Eventually my dad came down and told us that he had been in a lot of pain but that he wasn't going to hurt anymore, and I started to tear up but didn't know what to do. Apparently my brother, who was only 5 or 6 when he picked out that dog as a puppy, was holding that dog in his arms and crying at the very end.
I hope your dog is okay. I really wouldn't want that to happen to anyone else. Not so early. :'(