I have ferrets and a rabbit!  My rabbit is currently nine years old, and
has been living with ferret (three different ones) all of his life.  He is
about six and a half pounds; the first ferret he lived with was about three
and a half pounds, and my current ferrets are both more or less two pounds
each.
 
You can make a rabbit/ferret combo. work .. but in my experience, they
won't really "play" together, and their interactions together need to be
very short and very supervised.  My ferret Fred (now deceased) grew up with
Waldorph (the bunny), and they interacted well.  I could have them in the
room together (with very close supervision), and the most that would happen
was a chase.  Usually, Fred would tug on one of Waldorph's ears or nip
Wally's cottontail, and Wally would take off running.  Fred would chase
him ..  and then at some point, Waldorph would whirl around, and take off
after Fred instead.  When Waldorph got sick of the game, he'd snort at
Fred, stomp his feet, and chase Fred under a piece of furniture ..  and
that was that.  (I'd peek under the furniture and see Fred lying there with
big, round eyes, as if to say "Whew ..  glad I got away that time!")
Needless to say, this was all closely supervised.
 
My little Scooter also grew up with Waldorph, and he has a healthy respect
for Wally.  He finds it fascinating to watch Waldorph, and he loves to try
to sniff Waldorph's ears, for some reason.  Waldorph doesn't like this, so
he lunges at Scooter (very carefully, without touching him), stomps and
grunts.  Scooter runs under the furniture ..  and that's that.
 
Paddington is the one I have to be most careful about with Waldorph.  He's
the only ferret who did not grow up with Wally (Paddy was found as an
adult, and I got him through the FML ...), and he has a strong hunting
instinct.  He tries to jump on Waldorph's back and grab Wally's ears ..  so
those two are never allowed out together.
 
I think you can make the relationship work, if you supervise a lot, and
have separate run times and areas for the rabbit and the fuzzies.  Luckily,
my fuzzies sleep about 21 hours a day .. so I can have Waldorph out with me
during that time.  It's worked for me so far for nine years without a
single injury .. I just supervise really carefully, and I'm very careful
with the whole situation.  Good luck!  :->
 
- Ela
[Posted in FML issue 2605]