I am new to chickens. We bout 8 hens, and 1 rooster about 3 weeks ago. Up until last night, no problems. Right now they get about 1 hour out of their pen in the morning and then from about 4 until they go in their coop at night. We are feeding laying crumbles and they have access to fresh water day and night. Last night, we noticed one of the hens missing and found her in a clump of weeds where they had been eating, no chickens were around her. We thought she could possibly be laying an egg, but that later was not the case. All the chickens went into their coop but her. We picked her up and she was limp, we thought she was dead, but could see her shallow breathing. We brought her in and started giving her water by a syringe and she couldn't swallow, she kept stretching her legs out and curling her head all the way to her back and her eyes would cloud over along with making horrable sounds. She was in pain, but we don't know what happened. All of the other chickens were fine. They are all over a year old. This morning all of the other chickens seemed to be okay. Could it be something we are not feeding them that they need? Could she have eaten something that would have caused this? Could she have gotten bit by something that we did not see? Please shed some insight.