This is the second time this happened to one of our hens. She just stopped moving around. Wouldn't jump on roost, and just felt swollen and puffy. Stomach felt like full of water. Barely eating. After two days i lovingly put her down this morning. Having had to do this 3 times in the last year, i was relieved it went super fast. I don't know what causes these symptoms. Unfortunately lost 2 birds to hawks in the last month also. Think its time for LGD's.