http://www.smartgroups.com/message/readmessage.cfm?
gid=1423922&messageid=9762&startid=9766
 
No need to waste a lot of money to "test the mosquito."  Lets start
your ferrets on a heartworm preventative (ie Heartgard, ivermectin,
Interceptor, or Revolution).  They actually work by killing any 'new
heartworms" (Larva stages) that your ferrets were exposed to during
the past 30 days.  Thus it would cover this mosquito bite.
 
It takes roughly 6 months after the mosquito bite before the heartworm
test (Idexx snap Elisa test) will detect the heartworms (adult stage
in the heart).
 
Hope that helps,
Jerry Murray,DVM
[Posted in FML issue 4591]