Well, yesterday was more interesting than we bargained for. At suppertime Monday, Nicky wouldn't come down the stairs, so Dad Wood put on his leash and dragged him down (I wasn't home, and I'm a bit ticked at him for this). That night, Nicky was more restless than usual, not moving around, but shifting and whining softly. In the morning, he couldn't get his hind feet under him, and if I lifted him onto his feet, he would sag sideways. Testing him at the vets shows that while he still has muscle control, he's lost proprioception - the ability to tell where his hind feet are. Without that, he can't place his feet properly or make corrections to keep himself upright.
The vet say he has a bulging disc and has put him on Prednisone. If it's going to help, then he should show improvement in the next 48 hours. If it doesn't help, then we start discussing whether we have the money for back surgery for a basset. Cross your fingers, please!