It's tough to accept as she is not quite 2 years old, but Lucy is having difficulty with her hind legs, weakness that makes it nearly impossible to go up a step or even walk. Had to take her to the vet who x-rayed her, though it did not show much. Given her symptoms and how she is walking, he believes it is some kind of disk problem--it just couldn't show up on the x-ray. She is on restricted rest and some meds. I am supposed to watch for "knuckling" that will indicate a decline and then I…