Ok, then, that's what they should be on for cocci. The trouble is that if they're already fluffing up like that, plus bloody poop, it's rather advanced and there is more intestinal damage than if you'd seen it sooner-sometimes the signs are hard to catch, though. Get the probiotics or plain yogurt for them. That does seem to help. Farmers used to add nonfat dry milk powder to their starter crumble during an outbreak of cocci to help get them through it, though normally, chickens are not great with milk products other than yogurt with the good bacteria.