I have mainly Polish chickens who are 10 months old. They free range at least part to most of the day. Monday we found one dead outside. The only thing out of the ordinary was her vent was prolapsed slightly. Wednesday I had two hens acting sick. A Production Red who was swollen under her vent and bruising lower and a Polish who had a collapsed egg. They went into a crate but are now doing well and in GP. Today we found another Polish near death. She had broken the tip of her beak and was bleeding. After we found her she never opened her eyes, had trouble breathing and died within 10 minutes. Afterward we noticed her vent was also distended. We did a necropsy to see if there was any obvious problems. There were not - at least that we can tell. She is very fat. Here are pictures for those of you who know more. Is there anything that looks wrong? Are my birds dying because they are too fat? Advise?