If it is still red I would keep it wrapped until it looks better. That way when he walks it won't hurt & will keep dirt out of it until the nail grows back. Keep cleaning it & neosporin on it. I've seen these take about a week to get an outer nail growing just enough for you not to wrap it. If it takes longer, take him to a vet. If you do take him into the vet, they may give you pain meds and or antibiotics.