The last few days one of my cats has been walking wobbly...then today I was holding him on my deck and he wanted down so I put him on the railing...and he started to walk along it like normal but every few seconds his back legs sliped a little off balance and he almost fell..I picked him up and put him down and his walking was wobbly...when he stands his back legs look like he shivers...and he is walking wobbly. He looks uningured though...He is a young cat almost full grown and has always been healthy and playful. 2-3 of my others have gotten colds(runny nose and eyes, sneezing) but I treated them and he never got it. There is only one with cold symptoms right now....PLEASE HELP I have told all I know about the possible environmental causes to his problem...please help him...I cant afford the vet right now, but if I have to take him I will, but I need to know for sure so Im not out of money if he has something that will go away on it's own....thanks 4 ur help.