Sara- ferrets can get and give canine distemper to/from dogs.  also, people
and ferrets can give each other influenza (not COLDS, but true influenza.).
There may be a few other things i'm not thinking of, but nothing else leaps
to mind.  Oh, well, except there are some rare cases of fungal infections in
the ferret such as aspergillosis, cocciciodomycosis (not that i've ever seen
this, but it's in some notes of mine, from a Dr.Jeff Jenkins, DVM), and I
suppose that kind of thing could go back and forth, but people usually don't
get those, unless they are immune suppressed, and anyway, it says here they
are REALLY rare in ferrets.
 
Hillary
[Posted in FML issue 1406]