Why did my rabbit die?

Question
Last night I came home to find my rabbit laying limp on his toy. I called him and at first I got no response but then he opened his eyes and looked at me but didn't get up like he usually does. So when I picked him up he was limp in my arms. I tried to give him some food and he was able to eat a few bites. He started twitching but could only move his arms while his head kept bending back towards his spine. I put him on my bed but he couldn't stand, he just laid on his side. He kept trying to get up but only his arms and head could move. His hind legs were sticking straight out and his head kept bending far back. His breathing was very slow. He tried to get up again so I picked him up and he started to twitch again bending his whole body and head back and made a squeek like he was in pain. He never made any sound before so when I heard that I gently put him back on my bed. I could hear him trying to breathe then I heard him take a deep breath and watched him breathe out all he had left. He died after that but I still can't help but wonder what the cause was for his death. He was fine playing in the yard that day and then I put him back in his cage before I left. A little girl dropped him 4 feet and he landed on the concrete but that was three days ago. Please, I just want an experts opinion on why my bunny died, if he was suffering and for how long. Thank you.

Answer
Dear Briar,

I am sorry about the loss of your bunny.

Sadly, there is absolutely no way to confidently ascertain a cause of death without a post-mortem exam, preferably including histopathology of major organ tissues.  The signs you describe are very vague, and could have been due to any of dozens of different things.

If you noticed signs of unusual behavior before he died, then please read:

www.bio.miami.edu/hare/sickbun.html

which might give some clues.  But unless you can provide a lot more specific information, this is the best I can offer.  

If the body has been kept very cold (not frozen), and it has been less than 24 hours since death, a necropsy may still be possible, if you feel that would give you closure and peace of mind.  You can find an experienced rabbit vet here:

www.rabbit.org/vets

to call and find out what your options might be.

While the accident with the little girl happened three days ago, it might well have something to do with this if something ruptured internally.  A drop of four feet is very high for a rabbit, and it he landed wrong, he may have sustained a fatal injury.  A necropsy would reveal this.

I am very sorry for your loss.

Sincerely,

Dana