My 2-year-old Rhode Island Red was unusually quiet a few days ago, and when I approached it was clear that one of her legs was not functioning. She hopped on one foot and flapped her wings to move about, and when she next settled down, her leg was stretched out in front of her rather than being tucked underneath as usual. She has managed to get around minimally and to get in and out of the coop, but when I put her down this morning next to the water dispenser, she greedily drank...so probably not getting to food or water normally. I hate to lose her but don't want her to suffer. What do I do?