Hi, if he is bleeding from the nostril I would just wipe the blood and see if it happens again. If it keeps bleeding then yes I would bring him to vet, could have damaged or broken something in the nose area. If its a cut you can treat it with Neosporin without pain reliever, the painreleiver one will kill your frog. AS said its just probably nose rub, if its a cut keeping it clean and the Neosporin should help it heal. Hope he gets better.