Help! 7 mo hen can barley lift head-leaning a lot to the right-seams drunk
She may just be dehydrated and weak from not eating much, but coccidiosis can also be a problem, especially when staying inside in a small space. I would give vitamins and electrolytes in the water, and try to make her drink as often as possible today and tomorrow. Take a little chicken feed, and put water into that making a runny gruel. Eating that will get more fluids into her. Coccidosis signs are lethargy, weakness, diarrhea or blood in droppings, standing around puffed up or hunched, and refusing to eat. The usual treatment is Corid (amprollium) 1.5 tsp of the powder per gallon of water for 5 days. It won't harm the other one. Standard time for keeping new chickens quarantined is at least 30 days or more. I would also read about Mareks disease just in case her symptoms get worse, or she becomes lame.