We have been raising rabbits for about two years now and have butchered a few dozen to date. Today we decided to take care of a couple. Well here is the odd thing, their abdominal cavities had fluid in it. There was not a large amount, but enough that it could be seen once it was skinned. It was clear, looked like water. These two rabbits were approximately 16 weeks old. The only thing that I noticed while they were growing was one didn't seem to gain weight as fast as the others but he did gain and appeared healthy. All organs appeared normal and healthy. I'm concerned they may not be safe for us to eat. Has anyone else seen this? Should I be concerned? What causes this? Thanks in advance for any info.