Hello. I have a Silkie hen that seems to be constantly twisting her head around kind of like a snake, she tilts her head back a lot too, and she hasn't been eating much. She also has trouble drinking because of her head and seems to tilt it right back and then can't swallow it. I've seen this in one of my other hens a while ago but she ended up dying. Is there anything I can do for her, or anyone who knows what is wrong? There is rats in the barn we keep our chickens in, maybe she ate some rat poo and became sick? I have isolated her in a warm pen (temperatures are below freezing here) with an americauna, and have been putting tetracycline in her water.