Today, she seems lethargic and is sitting around a lot
They are still on medicated chick started, and I have electrolytes, amprolium, and probiotics in their water. I have them on amprolium because I got 5 week old chicks a few weeks ago who had coccidiosis. They are full recovered now, but I have it in their water as extra preventative. Two of the coccidia birds who fully recovered a few weeks ago,
How old is she?I try to keep diatomaceous earth in their coop to keep the mites and fleas away
Is she laying eggs?
How long exactly have you been giving Corid? just curious.
I would check her for lice/mites, look inside her ears for any debris/mites/infection.
I would also check to make sure her crop is emptying overnight.
I suggest that once you finish the bag of medicated chick starter, transition to unmedicated. At 5 weeks and beyond, if the chicks have been treated and they are in the environment in which they will be living, then they should have built resistance.
Let us know how your checks come out. If you can get photos of her poop that may be helpful as well.