I have a BO hen that is about 6 months old in a mixed flock of 26 birds. Last night I noticed her chest seemed very large but thought that maybe she had stuffed herself getting ready for the cold night ahead. DH let them out this morning but did not check her. Just went out to check the water and break ice and noticed her shaking her head and throwing up some. I caught her and her chest/crop is squissy and soft and very large. I did massage her alittle and she she did throw up a very small amount. I have put her in a rabbit hutch with no food or water. Could not tell you about the poop since so many of them, but have not noticed anything different in any poop. What do I need to do from here? They have free choice Layena crumbles, grit, oyster shell and water at all times. No one else seems to have this problem. They are given BOSS about two handfuls everyother day and about a handfull of scratch twice a day.