I would suspect that your sick ones aren't ingesting the medication in enough quantity. With Corid I usually see the bloody poos disappear in 24 hours. They HAVE come back a few days after the Corid was stopped, and then I had to do another round of Corid.
So I would try to several times a day...
http://www.justanswer.com/pet-bird/1e1tv-chicken-bright-yellow-foamy-droppings-please.html
if you scroll down they have a question about yellow foamy droppings and the answer is worms
I have seen these droppings in worms before. BUT your chickens are pale and near death from coccidiosis and I...
Please see this, as it says "yellow and foamy" can be coccidiosis (p.5 U of Kentucky)
http://www2.ca.uky.edu/afspoultry-files/pubs/Anatomy_Digestive.pdf
Wormers are very hard on chickens and if they are near death can kill them. Additionally, it is recommended that you not worm before 18 weeks...
https://www.backyardchickens.com/t/191920/well-water
see post #7
I don't know about nitrates personally, but here is another link:http://www.bae.ncsu.edu/programs/extension/evans/ps&t-42.html
You can feed them different foods while on Corid. You just don't want to give them artificial vitamin packs and the like while on Corid, as the Corid is trying to replace thiamine uptake in the cocci. So if you give lots of thiamine then you are making it harder for the Corid to work. That is my...
I agree with dawg53. If there is still actual blood (not shed intestinal lining) in the poo, then that chicken would
need more treatment. I have a couple of times had to go with two 5 day courses, as the bloody poos came back after a few days.
If you cannot determine who is pooing actual...
I forgot to say you're welcome (from the previous page of posts)! Thanks for thanking me! Mostly I'm just very grateful Sarah seems to be on the mend!
Your cat is jealous! Mercy me!
No, Corid is a thiamine blocker and thus they aren't receiving their thiamine during the treatment. If you kept them on it forever, they might get a thiamine deficiency (is my understanding of this medication). I consider Corid so essential to chick-rearing that I won't have chicks around...
Corid 9.6% solution- that's the right stuff.
Take 9.5 ml and put it in a gallon of water. Mix it, and give that to them as their only water. Change solution daily. Give for 5 days. Repeat course if coccidiosis signs come back (have had to do this myself)...