My 3 year old New Hampshire Red hen has always been skinny but over the passed few months, shes gotten even more skinny. She's had diarrhea for a couple days but then it went away. Also, she had a few fits of increased water intake where she would jump off the roost in the evening to drink for 5 minutes. I took her to the vet and she said it may be an impacted crop, which i checked in the morning and it was empty. While she is still skinny the other symptoms went away. A few nights ago i noticed she gaped her mouth once or twice, and tonight, she is doing the gaping constantly. I'm really nervous about her and don't know what to do! None of my other hens are showing any symptoms at all. Any ideas? Thanks so much!