We lost Nels to CDRM two years ago end of this month. We didn't have any massive signs to his problem - in fact was our clipper who brought it to our attention when she said that he had grumbled with the harness and they had had to muzzle him (very unusual) and he struggled to walk back to the car. That was April '07 and we took him to the vet. As he was insured x-rays and tests ensued. Was awful in a way as the specialist vet (who we were referred to) did suggest a little cart for him as an option, after an MRI but in our opinion it was too late as to us a cart just wasn't an option. Our house isn't a mansion, and the thought of him trolling about in a cart was just, well awful really.
So, we let him go and I can just see the little tinker being a little tinker at Rainbow Bridge - although as he was first and foremost's my mother-in-laws boy, and she passed before him so I hope he's now frolicking with her at some undetermined place which is just heaven for both of them