I don't know why the vet would say only half the amount we usually give chickens, but I've always given them 9-10 cc/ml per gallon for 5 days. If they are dying, you must hit them hard. Amprolium is not an antibiotic so it won't harm them. The preventative in medicated feed is amprolium and the treatment for cocci is the same med at a higher dosage for treatment. It's just a thiamine blocker. If you dose too low and they're already dying, it won't do them any good, IMO.

all i can do is hope and pray she hangs on til the meds arrive. from what speckled told me the bottle i ordered should last me a good while just incase i run into this problem again. however i do believe in my heart that i caused this problem un-knowingly. just because i raised my first flock without issue i thought i was good to raise the second flock. little did i know its probably because of my first flock that these babies developed cocci! when i put the babies out into their own private coop/run that i built (located a foot away from my main flocks coop/run) it never dawned on me that my larger chickens probably pooped in the new coop/run as i was building it. the older flock gets free roam of my back yard and while i was building this coop/run my biggens would run in and out of the structure. sometimes they would nap inside of it. i should have done my research or homework better. because of my lack of knowledge i honestly believe i caused this