I just discovered my hen lying in the pen. She appears lethargic with her wings hanging down and her comb and wattles are very pale. She's also panting and her feathers are ruffled and matted. I don't see any wounds. The coop is completely enclosed so there's no way a predator could have harmed her. She's also the alpha hen. I didn't notice anything out of the ordinary yesterday or earlier today. All of the other chickens are fine. I'm giving her some electrolytes. I have no clue what this could be. Any ideas? Thank you!