well yes it could be ring worm but one of my boy cats that i had that all a sudden one day i notice his hair was missing in one spot more and more hair would be missing each day. it was on his tail and went on his back it didnt get to bad. but we took him to the vets they gave us shampoo to wash him with. and then he told us to try this cream called TOLNAFTATE but i didnt get to see if it was helpin any better because he died from getting hit by a car grrr boo hoo he was my favorite cat he will be in my memories FOREVER good wishes to him sorry if im not good help well any ways good luck