Another possibility occurs to me..... Fatty liver syndrome which can be associated with inappropriate diet and/or lack of exercise (usually too much carbohydrate....scratch/mixed corn) that causes fatty deposits around the organs and can cause a build up of fluid in the abdomen (ascites). As with internal laying, the fluid can be drained using a large gauge hypodermic needle and improving the diet and adding a vitamin B complex supplement to support the liver may help to improve the condition along with perhaps more space to scratch and forage, to improve exercise levels.... reducing access to food and cutting out all treats except greens.
PS. I love the term ...
PS. I love the term ...
Doing DIY necropsies can be very enlightening if you can get over the emotional trauma and ick factor and perhaps prevent further deaths in the flock by adjusting flock management system/diet/worming etc. I appreciate that not everyone can justify the cost of getting it done professionally particularly if only one bird has died, but having a look yourself and taking a few photos of the organs and anything that looks unusual and posting them on the forum can be beneficial not just for yourself but others can learn from them too..... hoping it doesn't come to that with your girls just yet though!and look under the hood so to speak