There is soooo much more than coccidia that can cause bloody diarrhea in a puppy, and much of it fatal if not caught early, so kudos to you for taking this seriously. I would get a puppy formula or goats milk to add to his food, enough to make it like a thin paste, not liquid, not solid. I wouldn’t change foods right now, unless he is on something really bad. His poor system has already been through enough. I would add both probiotics and digestive enzymes to every meal until he is stable, and for at least a copule weeks after that.
