Agree with Longblades, if you have no result and there is a drastic change a wait and see approach may not work. Im not a vet but my dog was dragging his leg somewhat when it fell out of place from a luxating patella. But if your dog is falling over too this is worrisome. Did the vet palpate the spine and the legs? Did your dog receive anti inflammation drugs to see if this problem was pain related? Would try and get a second opinion.