It definitely sounds like the little ferret has an insulinoma, but with a
low WBC and low RBC/HCT, I would put her on antibiotics (as well as the
pred) in case of infection, and some vitamins would help too.  Then I'd
recheck the bloodwork in about a week or so - if it's not increasing, then
I'd suspect something more serious that's affecting her bone marrow (like
some cancer).  If she's not eating well, I'd also forcefeed her with some
babyfood or a/d or duck soup regularly.  The fecal check is a good idea
also.
 
K. Ball DVM
[Posted in FML issue 3314]