>You want to look for a vet who is board certified in animal dentistry
>and/or oral surgery.
 
That's a very good suggestion.  If you simply go to the yellow pages here
on Yahoo, and type in your home town and the search keywords "veterinary
dentist" - you'll probably come up with something.
 
Ferrets don't really get cavities, but you may be looking at a broken
tooth, with a slab fracture showing the pulp cavity.  Ferrets get a type
of cavity-like lesion underneath the gumline called a resorptive defect,
although I've never seen one (although I've never much looked - but I'm
going to start).
 
with kindest regards,
Bruce Williams, DVM
[Posted in FML issue 3738]