8 week old chick ate layer feed for 2 weeks

[Climbingalbatross]

I will start off with the backstory. I choose to purchase bantam sexed chicks 2 months ago, and opted about 2 weeks ago, to sell some of the chicks I wasn't planning on keeping. Fast forward 2 weeks, the individual I sold some of the females to tells me that the 1barred rocks can fly up to the edge of her 4 ft barrier separating the chickens from her German Shepard. I bring back the barred rock chicks and notice that one hasnt grown in size and is lethargic. It seems to be missing a neck, round in appearance, and ruffled. I reached out to the person who bought them, and she tells me that they were integrated with 2 fully grown bantam hens. She kept them around chick and layer feed, but she didn't think they would eat each other's feed. Could it be possible that the chick ate layer feed for the past 2 weeks? What can I do to treat a high calcium level in a chick?

 

[Eggcessive]

There is not much that can be done about the chick eating layer feed. But it looks lethargic and pale, so I would treat it with Corid for possible coccidiosis. Dosage is 2 tsp of the liquid, or 1 1/2 tsp of the powder per gallon of water as the only source. It is safe for any others. Change it daily. There looks to be no bedding where the chick is, and I would add some pine shavings or other bedding, and keep it dry and clean. Paper towel would be okay temporarily. Offer some cooked egg and watery chick feed. You can also give 0.1 ml per pound of undiluted Corid orally each day with a dropper to her as an extra boost or drench. Check her for any mites or lice. Consider worming her as well.