My little three year old can't use his back legs. He can't stand up. This started about three days ago. We have called two vets, it is the weekend. So we keep getting the vet that is on call. They tell us he might be having a seriser and to keep him quite. But it has been about two hours now and he isn't getting better. They told me to give him some Rimady. Hr did eat, but has not gown to potty yet. Please tell me what elce I can do.