It's been a long time since the topic of Kennel Cough came up so I
figured these past BW posts and their reassuring information might be
useful.  Dr. Bruce Williams is a ferret expert veterinary pathologist
who is justifiably world renowned:
 
http://ferrethealth.org/archive/YG4145
 
>You are correct in that kennel cough is due to one of a number of
>respiratory viruses which pave the way for later infection by
>Bordetella by "knocking out" the local immune reaction.
>
>While Bordetella can conceivably (but very rarely) infect other
>mammalian species, it is generally pretty well conserved to dogs,
>and poses little threat to ferrets.  Ferrets are also not sensitive
>to the common viral infections that facilitate kennel cough, with the
>exception of one of the rarest, canine distemper.
>
>Long story short - nothing to worry about with the current precautions
>you are taking.
 
http://ferrethealth.org/archive/YG11643
>Kennel cough is not a real problem in ferrets, and I would not
>recommend vaccinating for it. Kennel cough is a non-core vaccine in
>dogs and cats, and is generally only given to those who are likley to
>contract it - those in shows, being boarded, or around a lot of other
>dogs or cats.  It is most commonly used in dogs who board at the vets'
>and only rarely in cats.
>
>While ferrets are susceptible to one of the agents that causes kennel
>cough in dogs and cats - Bordetella - I have yet to see a spontaneous
>case.
>
>With the problems that may be associated with vaccinations in ferrets,
>I would be dead set against using this in ferrets without an established
>need.
 
http://ferrethealth.org/archive/SG4987
>Kennel cough in the dog is a combination of viral and bacterial
>infections and is specific to the dog.  While your ferret has a remote
>chance of picking up the bacterial component, the syndrome of kennel
>cough is not a consideration in the feret.
 
-- Sukie (not a vet, and not speaking for any of the below in my
   private posts)
Recommended health resources to help ferrets and the people who love
them:
Ferret Health List
http://www.smartgroups.com/groups/ferrethealth
FHL Archives
http://ferrethealth.org/archive/
AFIP Ferret Pathology
http://www.afip.org/ferrets/index.html
Miamiferrets
http://www.miamiferret.org/fhc/
International Ferret Congress Critical References
http://www.ferretcongress.org
[Posted in FML issue 5309]