Starting about 2 weeks ago my Queen of the Coop Americauna Gretel, would end up on her back unable to get up. When I put her right side up she would be a little wobbly at first, but then back to normal. About a week ago she stopped walking altogether, no balance/strength? There are no visible injuries and I don't feel any breaks. At first I thought Mareks, but her eyes are normal and the balance issue seems to be more right side dominant. By this time she had gotten quite thin and almost overnight seemed obviously sick (I didn't notice at first because she is such a fluffy girl) and I have since been keeping her separated from the other birds. After some some serious spoiling she seemed to get better (minus the walking), more alert and scooting around a bit. I cleaned up her butt and trimmed her so the poop wouldn't stick, hand fed her to her hearts content and I was feeling very hopeful. But then yesterday she seemed to take a turn for the worse... she will eat some, but hardly touch her water and now she is breathing heavier with her mouth gaping a lot. I don't have any experience with sick chickens and I am heartbroken with worry that I can't make her better...any ideas? Worms? Low calcium? I only have 5 girls and they have pretty much my whole back yard to run free. They eat crumbles, plus daily "treats" of either yogurt, fruit, greens, oats, grains, crickets, etc. Her poop seemed a little runny at one point, but seems fine now. If there is any other information that would be helpful let me know!