I don't write very often but the subject of giardia is one I am experienced
with.  I've been a veterinary technician for 22 years and have found
that veterianarians, tecnicians, and even some laboratories will often
misdiagnose Giardia.  The yeast (a nutrient) in the food they eat passes
through in their stools and looks similar enough to giardia cysts that it
is mistaken for them.  It is easy to determine if this is the case.  Just
have your veterianrian crush up a couple pieces of the food your ferret
eats, mix it with water, and look at the liquid on a slide under the
microscope.  Some ferret and cat foods have the yeast and some don't.
Remember the yeast is not a bad thing- it's just there not causing any
problem.  I suspect you might see more of them when the ferret is having
diarrhea just because more of them pass through undigested.  Holly, I
hope your veterianarian or hhis or her technician will be willing to check
this out.
 
Nancy Winter
[Posted in FML issue 3289]