Anyone know what's going on please?

[Hogs and Horns]

We got some new chicks back in April. They did great in the house when they first arrived, then later in a large horse trough in the coop (still with a heat lamp) and then they were moved into a smaller coop in the yard. Since then, maybe a month, three have died. Today I noticed another one looking a bit abnormal. She didn't move around much, and seemed uninterested in food or water. She seems to be paler in the face than her same-breed sister; they are French Black Copper Marans. So we moved her to the horse trough alone, with a heat lamp, water, and food. Our concern is that it seems to be an environmental problem in that coop, but we can't figure out what it is. If you have any ideas what could be killing our chicks, could you please let me know? Here are some photos I took of her this morning. Thank y’all so much for any help or guidance you can provide.

 

[sourland]

Are they passing bloody feces? If so you are dealing with coccidiosis.

 

[ChickenWhisperer101]

I agree with sourland. I had to deal with coccidiosis last year and it killed 3 of my girls, luckily I treated the rest in time.

 

[Hogs and Horns]

We have seen nothing abnormal about their droppings. Thank you for asking.

 

[MysteryChicken]

Could they have gotten into something toxic?

 

[DarkWater1929]

Have you given them a good once over for lice? I always suspect it, when they get pale like that. I would never have thought that lice could drain a bird to the point of death, until, years ago, they killed two of my hens, before I figured it out. Have a good search around their vents, especially. Then, a wash with dawn dish soap (I accidentally killed a bird once, using flea shampoo. I still feel wretched about it), low temp, or cool blowdry, followed by some sevin dust, or other chick friendly bugaside, might do the trick. I hope you figure out what it is! She looks like such a sweet baby!

 

[Chicalina]

I would do a broad treatment for internal and external parasites (ivermectin and permethrin) and also treat for coccidiosis. Those seem the likeliest culprits.

And after treatment, boost with some vitamins and electrolytes, and maybe some high protein feed for a week.