Unexplained Rabbit Death

Question
Hi

My Holland Lop, Hazel, (female, spayed, one year old, shares an indoor hutch with another rabbit [Silver, another lop, neutered, male] )died suddnely last night.  She has problems with her teeth, maloclusion (sp?).  She went to a rabbit vet a few months ago to get her front teeth pulled (she got spayed at that time too), but one of them was broken off and stayed in, so on last Monday she went in to get the last one removed... anyway when the first three teeth came out I had to hand-feed her baby food for a while because her mouth was sore, but this time the vet said that she wouldn't need that because it was only one tooth.  She seemed to be eating and drinking fine.  On friday, I left for New York for ten days, and my trusted friend was in charge of caring for my pets.  Last night she heard loud noises, thumping and stuff, coming from the cage, which is not unusual because my cage is a two storey and they like to play chase up and down the stairs.  Hazel seemed active, alert, and healthy, although she doesn't know Hazel as well as I do and could have missed something about her behavior.  This morning, she found Hazel lying on her side in the hidey-hut, with her eyes open but not breathing.  She had to actually pry the dead rabbit off of the floor with a piece of cardboard because she was stuck to the floor with her own urine.  
I really want some answers about what could have happend to her... and I need to know if it could be dangerous to my other rabbit.

Also, could he get depressed or sad or something without his lifetime roommate??  They came from the same box in the pet store and could even be siblings, though im not sure... they love to groom and play together.

Would getting another rabbit be a good idea to help him?
If so, I have an extra hutch where it could live while being gradually introduced to Silver, who is always calm and sweet with other rabbits.  Do you have any tips for introducing rabbits?

Anyway thank you!!
Kaela

Answer
Dear Kaela,

I am sorry about the loss of Hazel.  Unfortunately, only a necropsy/ post mortem exam would reveal the cause of death.  It could have been any of dozens of things, from acute infection to a cardiac problem.  There is simply no way to know without more information.  But you can rest assured that it is not very likely to have been contagious.

Yes, her mate will grieve and be depressed, and you need to watch him closely for signs of ileus and grief so severe that he gives up:

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

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

It would be a good idea to contact your local rabbit rescuer and arrange some "blind dates" to let him choose a new friend.  DO NOT bring home a surprise friend, as this will more likely result in bloodshed than in cuddling.  Rabbits are *very* territorial and picky about their mates, and it is extremely important to let him choose.

You can contact your local rescuer here:

www.rabbit.org/chapters

I hope that helps, and again, I am very sorry about your loss.

Dana