I just bought 3 new pullets, 2 are Old English Bantams and the other is a Pyncheon. I have them quarantined right now and I noticed on all 3 of them, there crops seem to be more to one side of there chest, noticeably more to one side. One of the Old English was doing a twisting of her neck involuntarily, looked like she had hiccups and was moving her head side to side during it. Then I noticed her neck is in a S shape. They all eat, drink and poop normally. Other than everything above they act like normal chickens. I'm getting some PolyViSol without iron today but, is this contagious? How long does it normally take to correct and if it doesn't get corrected with the vitamins, what do I do?