Nikole,
It is my understanding that tattoos on ferrets are put there by mills or
farms to either identify the stock or as a tracking mechanism to show wheter
the animal has been neutered yet.  Any shots received by one of these
ferrets is simply a short term canine distemper booster which runs out four
weeks after its administration.  I hope this helps.
 
Alicia
[Posted in FML issue 1912]