My beautiful 8 month old Silver Laced Wyandotte did not come out of the coop this morning. I enticed her off the perch with raw egg yolk but when she tried to eat it she made a barking sound -- a single-syllable hiccup. I put her in a playpen with food and water and she periodically makes this sound but is not eating. Her crop has some liquid in it (nothing solid), but it is not distended and she is not spitting up any of the liquid. Any idea what I am dealing with and what I can do?