until you can get Amprol go to First State Vet supply online just google it. Please put powdered milk in their feed, it cant hurt and might just save the last one. I have been through this before, the powdered milk is not a cure but coats the intestines reducing the damage the cocci is causing...
my first guess is cocci, any blood in their poop? try adding some powdered milk to their feed and yogurt pro-biotic mash: starter feed, yougurt (the real kind) some shredded apple, and butter milk. Mix all together and feed. See if that helps.