I have had my chickens about a year but they have been, overall, very healthy birds so I am new to the diseases/illnesses they can get. I have a 2 year old australorp hen that has been acting not herself for about the past week. She seems uninterested in food and now sleeps on the floor of the coop instead of on the roost with the other girls. Compared to her "sisters," she has lost coloring in her comb and waddle. They were a bright red, and now they are more of a pale, chalky pink. She also has pasty stool that has been sticking to her. Her eyes are clear. Her breathing seems fine. She just seems...down. Weak...I don't know what to do. Antibiotics? Hope for the best? I have a couple hens that have scaly leg mites and I am treating them for that. I have been treating all my hens to be safe but her odd behavior began before the mite treatment so I don't think it is related to that. I don't want to lose her. Please help!