The recommendation from Rhone Merieux, manufacturer of IMRAB-3 recommend a 2
week waiting period between the canine distemper vaccination and the rabies
vaccination.  Dr.  Mills (RM) believes that giving the two close together may
lead to such reactions.  They are collecting information from around the
country on allergic reactions in ferrets after receiving a rabies vaccination
using IMRAB-3.  You may want to have your vet contact them with the
information.
 
Last fall we had two of ours experience similar reactions after vaccination
with the rabies vaccine.  It seems to occur in animals receiving their 2nd
through 4th vaccination.  If they don't have a reaction after that they
probably won't.  Dr Mills recommends no further vaccinations with the vaccine
if the ferret experiences a reaction.  If you feel that you must vaccinate,
the ferret must recieve pre-vaccination treatment, which as you found out, is
not always effective.
 
Dick Bossart
[Posted in FML issue 1085]