D.C.
Yeah that sounds like thrush to me. My baby had it when she was around that age and it made her entire tounge white. It doesnt wipe off with a cloth, well it will but you have to put a lot of prussure and it bleeds. Thats the old way of handling thrush. What you should do is gently see if it comes off, if it does not then call your doctor and tell him whats wrong. He may not need to see the baby if you tell him the symptoms and have the number to your phramacy he can just phone in a prescription for you. I've never heard of a baby's tounge turning white from formala, just thrush.