I have had several rabbits die lately. They were in different cages. I had a very large New Zealand/Californian. She was very healthy. I did a necropsy in her. She had watery fluid in her diaphragm. Another one had lost a lot of fur on her back, same breed, and ears. It looked like maybe she had mites. She lost use of her back legs. The other just stopped moving and died, same breed but smaller rabbit. I usually have very healthy rabbits. I don't want to lose anymore. I have quite a few rabbits in different cages. They live in a building and had automatic heated water system. They are on pellets, hay and occasional fruit or veggies in small amounts.