Hi, My cat showed signs of limping, pain and unusual gait. The symptoms have progressed to not being about to use his back legs. He can move them, he is just choosing not to move them? He pulls himself along by his arms typically to get close to his liter box, then I pick him up so he can use it. We suspected a fall, but are still unsure of what it could be. His blood tests and x-rays came back totally normal. Any ideas?