I have a hen who suddenly is very pale in the comb and face, and she refuses to move much, preferring to sit down in the middle of the coop in the sun. Her eyes are a normal color and she has no trouble keeping them open, but she has been breathing with her beak open. She hasn't eaten or had water all day, but I did see her poop and the consistency and color is normal, hopefully ruling out cocci. However, I did find a small (3") pool of blood in their house this morning, absent any fecal or egg matter. I felt her for eggs and she doesn't seem to be egg bound. She stopped laying about a year ago (I don't know her age, as she was plucked from a large farm as an adult) and the other two hens I have from the same farm are still laying and don't seem ill at all. Any ideas? Could this just be old age? Is there anything I can do to make her feel better?