Becca,
 
Your ferrets can cross the US-Canada border either direction with proof
of rabies vaccination.  It used to require a complicated permit, but that
ended a couple of years ago.  Even before that, my ferrets crossed without
the permit, because few border guards knew anything about it.  Now we
regularly cross at Prince Rupert and Vancouver, and sometimes more obscure
crossings on the Washington or Idaho border, twice a year in our annual
pilgrimage between home and graduate school.  I don't mention the ferrets
if they don't ask, but I have never, ever, had a problem.
 
-- Kim and the Five Ruling Ferrets
[Posted in FML issue 2695]