Not sure what pred you're using, but my ferret found the regular pred too
bitter.  We had our vet do a prescription for pedia pred (prednisolone),
it's not as strong, so the prescription will call for a bit more to be
given.  I put it in a tiny dish with a drop of ferretone and Mikette
licks it up on her own if I hold her.  Some pharmacies will also compound
with flavors like raisin I think.
 
Hope this helps a bit.
Good luck
Risa
[Posted in FML issue 4749]