I've been away for a few days and I've come back most of my chickens are fine except one silkie, she can't hold her head up, shivers and is incredibly listless. I think she's dehydrated, what can I do to help, she is in the bathroom with a heater on low wrapped in towels, I gave her a drink and now she's kinda sleeping and convulsing occasionally please help I'm and desperate to save her.