One of my two likes the dried liver treats I got for the dog.  They sort of
look like cubes of styrofoam.  You can get beef or chicken.  They are all
protein, no fat.  Of course they both like little bits of doggie
biscuits/bones.  Sometimes I even hand feel a piece of cat food or dog food
as treat.  They don't like raisans but do like bannana.
 
One thing I do to reinforce to my dog that the ferrets are higher in the
pack chain (and therefore not to be touched) is to feed them their treats
first in front of him.  He waits for his and gets it after they get theirs.
And I always give him one when they get one so he doesn't feel resentful
(just in case that's possible).
 
Mary, Boris and Giesela and Booker (who doesn't really like the ferrets:(
[Posted in FML issue 2026]