Mostly we know what it isn't. It isn't a disc problem or a spine problem.
What is seems to be is a neurological disorder, which is a broad category. Although it isn't, think MS in humans.
We are waiting for more test results to see just what it is. We hopefully should know more by tomorrow.
Jethro send his thanks also. He is the black cat in the piccie. Ducky is the grey one.