Susan
Dr. Charlie Weiss often recommends surgery before medical treatment for
insulinoma.  If you wait too long to do surgery, the tumors will have
spread and the ferrets condition worsened to the point where surgery may
not provide much benefit.  See the insulinoma discussions at
http://www.miamiferret.org/fhc/
for more information.
 
I agree with you that 3 hours and $600+ seems very out of line.  Also some
vets would consider a reading of 72 to be borderline.  Were the tests done
after no more than a 3-4 hour fast?  With the absense of symptoms, there
may not even be any visible or palpable tumors yet.
 
In this case, waiting and getting a second opinion is certainly called for.
 
Linda Iroff
Oberlin OH
[Posted in FML issue 2976]