I have a 3 month old brown leghorn pullet that is has terribly shaky legs. She was normal until Sunday morning she started withdrawing from the flock. Upon further inspection, she can walk but her gait is wobbly and her legs tremble while standing. She's in isolation in a dog crate in the house, eating and drinking normally, alert, and flighty (like I'd expect with a leghorn). I've added vitamins and electrolytes to her water but in 24 hours of cage rest I've seen no improvement. Any idea what this could be and how to treat it? None of her other flock-mates are experiencing this issue.