Recently rescued aged cat has been confined for the past three weeks pending his release into the yard. He is being treated for worms. In the last few days he has begun to lick the fur off of a large area on both sides of his rib area. When he first started on one side, we applied ringworm medication to the area, but that resulted in him starting in on the other side. I am suspecting an obsessive/compulsive behavior rather than a genuine skin problem. Any ideas?