
That's the problem with cdrm, you just can't tell how quickly or slowly it will progress. We really noticed with Ellie last summer, we took her to the beach and her back legs seemed to be criss-crossing so really hers seems to have gone worse more slowly than your boy, though she is finding more and more difficult to get up now, though this may be as much due to the arthritis as we've had to stop the anti-inflammatories for now. According to our vet the cdrm doesn't cause her any pain, she just can't use her legs, though I feel that she worries about it and that causes her as much stress.
What lines is your boy from? I'm just interested because I'm 'into' gsds, I'm not asking because it has anything to do with the cdrm, because I have no idea if it comes from certain lines or not (pm me if you prefer).
Maybe it's just because you're more aware of the problem that it seems worse? I know what you mean about it being heartbreaking, I feel like I'm watching my poor girl fade away from the giddy young thing she was.