Hello. Today I noticed one of my 1.5 year old leghorns, is acting weird. This morning when was in the nesting box for over four hours, she never layed a egg. In fact almost none of my hens been laying any more. (I been getting three eggs a day, I have six hens and used to get six a day.) When she finally left the box I noticed her comb is bluish purple, and drooping far more then a leghhorns comb typically droops. She is lethargic and Is constantly drinking but not eating. The rare times she eats she throws her head back like she drinking, unlike my other chickens. Her crop feels full but I can't check my other chickens to compare, they wont let me. I think this is a impacted crop or something respiratory. Any ideas?