>However, the results of the lab bloodwork came back as follows:
>
>   - excessively high red blood cell count
>   - 72% of red blood cells vs serum (normal values in the 50% range?)
>     in a centrifuge test to separate sells from serum
>   - 15,000 cells per microliter in the count of number of red blood
>     cells per field on the slide (normal 6k-11k/microliter?)
 
Dear X:
 
Mike's theory of dehydration has merit, and is always the first thing to
rule out.  In such a case, I would repeat in 10-14 days, as long as this
ferret does not show any signs of distress, continues to be active, eat,
drink etc.  Before jumping to any conclusions, let's make sure this is
not a spurious finding.
 
There are very few diseases that cause an elevated PCV.  Polycythemia
vera is a very rare neoplasm of the red blood cells; I am currently
corresponding with the owner of one case, in which the PCV exceeded 80.
The treatment for this disease is simple removal of blood - which is
titrated to a level which keeps the PCV at a normal or near normal level.
Sounds a bit barbaric, but it is universally done in all species and works
well.  In this ferret, only one or two bleedings had worked very well.
 
But let's rule out dehydration first.
 
With kindest regards,
Bruce Williams, DVM
[Posted in FML issue 3588]