Her T3s look fine and there is no other indication of thyroid problems, her
BUN and creatinin levels are perfect.

The only abnormality was a low white blood cell count.  This is ominous
because it's the second time within a year that she's had a low white blood
cell count (the last time was back in June of 2005) and that could point to
FIV.  I have to get on the phone to all her past vets to see if she has ever
been immunized for FIV because if she doesn't spring back to health in the
next week or so they want to test her for it (and if she's ever been
immunized for it, it will show up as a positive reading).

They gave her some Clavamox to keep her from getting any secondary
infections while she's in a weakened condition.

Any ideas anyone?  Comments?  Like experiences?  Do you think I should take
her to her regular vet (this would probably involve about a $300 - $400 fee
if they want to retest, and it was her regular vet who'd tested and found
the low white blood cell count less than a year ago).

I'm getting kind of panicked here - do you think she could have contracted
FIV in any of the short forays she's spent when she escaped outside?  Should
she be segregated from my other cats?