Some areas are already in the bad seasons for those critters and some
will be there soon.  Go to this post:
http://groups.yahoo.com/group/Ferret-Health-list/message/13103
to get an assortment of vet explanations and info that will help save
ferrets.
 
I have sad news to impart.  Some may recall that I have a set of relatives
who live far away and who had an abandoned ferret but should not have had
any.  They simply would not read about health things, didn't get shots
like they should have, would not read the materials I supplied (along with
a lot of supplies -- real lot), would not give heartworm meds even though
they live in an area with a lot of those, etc.  The level of neglect was
not enough for legal action, but was enough to kill.  The ferret died this
week at only about 18 months of age.  Cause is unknown.  After learning
about this yesterday it was very hard to sleep last night.
[Posted in FML issue 3783]