I have a 5.5 month old, not-yet-laying, Buff Orp pullet who is lethargic and panting. My flock free range when I am home, and they have been out and about for the last 3 hours. Several of them often make their way to the front part of my house. I went out to offer them a few handfuls of rolled oats and noticed that one was standing off to the side, not moving. Not interested in treats, nor in water when we brought her inside. Her breathing seems slightly labored - not heavy panting but with slightly open mouth, and the rate is a bit faster than I'd expect. She's not laying yet, but I don't think she's egg-bound (though I'm not sure I'd know with certainty). I don't think I see any bugs (I've never seen lice or mites on a chicken, so I am only going on the pictures I've seen). They have never been wormed, and this one came from a farm where she was vacc'd. The entire flock (all are more or less the same age) was treated for cocci about 8 weeks ago. I've cooked up some egg to offer her, though I suspect she'll ignore them. What should be my next steps? Edited to add: No interest in the egg. She's laying down (upright), but still panting. I put a tiny piece of the egg in her beak, which she did swallow, but still isn't interested in more. I can't feel any food in her crop at all.