Dear Nancy -
 
>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.
 
I'm glad you brought this up.  I agree wholeheeartedly.  While I generally
don't want to tell people to ask their vet if they are sure if it is really
Giardia, I am generally suspicious whenever I hear the diagnosis.  Ferrets
do have a lot of yeast in their stool, which is slightly smaller, but can
be easily mistaken for Giardia.  The big difference to the inexperienced is
that while both will move under the scope, Giardia moves in a more directed
fashion, due to the presence of flagella, and yeast just tend to roll along
on the eddies and currents of the fluid under the scope.  I liken yeast to
tumbleweeds - they have no ability to move on their own, but they are often
in motion due to other factors.
 
Truly, Giardia can be isolated from clinically normal ferrets - I think
that it gets blamed for a lot of diarrheas that spontaneous clear up on
their own.  The problem is that the recovery is often coincident with
treatment, so it looks like the treatment is working and the diagnosis of
giardiasis sticks.  But what am I telling you this for - you've been doing
this longer than I have!
 
With kindest regards,
Bruce Williams, DVM
[Posted in FML issue 3290]