Abdominal cysts in a chicken

Our 4 year old Dominique has suffered and finally succumbed to a massive amount of cysts in her abdomen. We know of no illness that she ever suffered from other than the occasional bout of diarrhea. She has always been feisty and very social. About a year ago, she began to lay shelless eggs and then a few with deformed shells, then stopped laying altogether. I noticed that her abdomen was large and pendulous. With research I suspected that she might have egg peritonitis. I drained some fluid from her abdomen that did appear to be egg yolk like in appearance. I continued to monitor her and she did have a few days of being very lethargic, sitting in the coop, not eating. I would offer her some of her favorite treats which she did take and she did seem to recover to her normal feisty self. Still no eggs. Periodically, I would check her belly and tap it for fluid accumulation. Usually I would drain about 200 cc of clear odorless fluid. I drained the fluid because as her belly would become distended, she had trouble walking with the bulk of it. Once drained, she could move around better. I would do this every month is so and assumed it was related to an egg peritonitis. I hoped that as she went through a molt, that her egg production would stop and she would have a chance to basically recover her normal abdomen. In January, she began to lay beautiful little round eggs again, but only for about two weeks. Then I noticed that her belly was becoming distended again. As I palpated I could feel multiple pockets of fluid. I drained as many as I could feel the reduce the distension. But, two days ago, she became very lethargic, fluffed and heavy breathing, this time she had no interest in food. I again drained a few more pockets of fluid, but to no avail. She died that evening. I opened her belly and this is what I found-tons of small fluid filled cysts filling her entire abdomen and up under her rib cage. There was no way I could have drained them all or even gotten to them all. I am not clear on what was going on to cause this to happen. All her other organs looked normal. There did not appear to be any egg yolk in her belly, so I am not sure if the original suspicion of egg peritonitis was the cause or not.

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