holland lop doe

Question
Hello,
Our much-loved white Holland lop doe died this morning, and when I saw your website I thought I would ask for your opinion on cause of death.
Petra was bought about 4 years ago from a pet shop.  She was already full-grown, and they didn't know exactly how old she was, but thought maybe 1 or 2.  We have had her for about 5-6 years.
Petra had 3 litters about 3-4 years ago, the third of which was successful.  She was never spayed.
About 3 months ago, Petra (who was living outdoors with a custom hutch for shelter, & had the run of the backyard) started showing signs of discomfort & inability to hop well, because of her back right leg.  This gradually worsened over the following couple of months, to the point where we had to bring her indoors to her cage for protection.  The vet said she had neurological damage to her hind end.  Her right hind leg trembled uncontrollably and more or less constantly.  It got bad enough that she could no longer support herself upright, and spent the last 2-3 weeks of her life lying on her side.  She ate & drank with our assistance, because moving around the cage became increasingly difficult & probably pianful for her.
She was eating well until about 2 days ago, but lost quite a bit of weight over the past few months.
Do you think it most likely that this is the result of an accident (ie. she got trapped in something & forced herself out), an attack (cat, other rabbit, raccoon, or our pet Cocker spaniel, who is curious about the rabbits we have, but doesn't seem to do anything with them once he gets up to them), or is it simply a malaise of old age?
We don't really know whether she was 6 years old or much older.  No less though.
Thanks in advance for your insights,

Leslie

Answer
Dear Leslie,

I am sorry about the loss of your friend.

A slowly developing paresis (weakness) in the hind end of a rabbit is often a sign of a parasitic infection by an organism known as Encephalitozoon cuniculi.  Unless your bunny suddenly developed an inability to walk and showed signs of trauma, I would think a traumatic injury from a predator is much less likely.

At the age of six, your bunny was not old.  But she was at the age when some rabbits who harbor the parasite begin to show symptoms, which can include hind limb paresis, head tilt, loss of renal function, and some other neurological signs.

I'm not saying that this is what took your bunny's life.  But it's true that the signs you describe are consistent with E. cuniculi infection as we presently understand it.  There is no way to know for certain the cause of death without a post mortem exam including histopathology of major organ tissues.

You can read a bit more about this problem at these sites:

http://www.veterinarypartner.com/Content.plx?P=A&A=490&S=5

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

http://www.rabbit.org/journal/3-2/e-cuniculi.html

I am sorry this comes too late to help your little girl.  There are treatments for E. cuniculi, though they have mixed success.  But it would require the help of an experienced rabbit vet who would recognize the signs of E. cuniculi and prescribe appropriate medication.  You can find such a vet here:

www.rabbit.org/vets

if you ever bring another bunny into your heart and home.

I am sorry about your loss.

Dana