I don't have one, per se, but here's what I would do.
 
This is just a basic sweater, but once you get the pattern down you can
do all sorts of things with it.  You could try changing yarn colors, do
it with a SC throughout.  Or different stitches/color combinations.  You
could even do a rib stitch on top and/or bottom.
 
I would use 4 ply and a G hook for a warm sweater, or baby/sport yarn and
a smaller hook for a lighter sweater.  Or to go really fast and make a
super warm sweater you could hold 2-3 strands together and use an I or K
hook.  (I've used this technique to make layettes and it's really pretty
if you use several different colors).
 
1. Make a chain that fits comfortably around the ferrets middle.  Join
   to form a ring, being careful not to twist.
 
2. Ch 3, DC in each Ch around.  Join to top of Ch 3.  Turn
 
3-?  Repeat #2 until sweater reaches just behind the arms.
 
4. Ch 1, SC in first 3-4 stitches, Ch 2, Skip two DC, SC in next St's
   around to last 4-5 St's.  Ch 2, Sk next two DC, SC in remaining 3-4
   DC.  (I say 3-4 because you will need to measure how much space you
   will need between front legs and adjust accordingly)
 
5. Ch 3, DC in ea SC around.  Join at top of Ch 3.
 
6. Continue #5 until sweater is long enough to cover neck, or where ever
   you want it to stop.
 
7. You may want to finish with a row of SC on both ends and around arm
   holes.  Also, if needed, you could decrees a few stitches after #5 to
   make it fit closer around the neck.
 
 
Good luck,
Shelley
 
BTW, this is my own pattern I just made up.  I didn't borrow it from
anyone else and anyone who wants it is welcome to use it.  Please don't
sell the pattern though, sharing is ok.  (you can sell the sweaters if
you want, that's ok with me).
[Posted in FML issue 4598]