There were others that referred to foods/herbs you can use w/your hens as well to prevent it -spinach and dandelions are all I remember. Some talked about tumeric tea to decrease inflammation, but dosage w/a chick would be really difficult to gauge. Wishing you the best!
Just bc I'm curious - she said it's arching it's neck back. I had failing keets do the same - but that's not the same as wry neck, is it? The causes don't match up, unless hens toss out failing chicks?