Two years ago, my little Zaque went through the exact same thing.  From what
I read, I would bet my very last dollar that it is fleas.  By the time we
got Zaque to the vet, they could not even get blood out of him.  We gave him
ferrettone and ferretvite.  We used a dropper to feed him kitten milk, and
force fed him soft food that the vet gave us (Sorry, I can't remember the
name).  After all that, he still did not get better.  So off to the vet we
went again.  This time he gave me an antibiotic for Zaque, he thought an
infection had set in.  This worked!  (along with a continuence of the
feeding process).  Another thing is Program is a wonderful product, but it
does not prevent the fleas from biting Weezie and ferrets have so little
blood to give.  We have found a waterbased flea product by 3M that is our
godsend in our little zoo.  It is very powerful and is harmless to your
fuzzie (or kittens for that matter).
 
Make sure Weezie is getting lots of nutrients, lots of TLC, and get rid of
the rest of those nasty fleas!  My heart goes out to you.  Good luck and
please keep us posted, if not on FML, then e-mail us directly.
 
Sular, Zaque, Symon, Kara, Gershwin, and Chester
[Posted in FML issue 1707]