Hi i found the recipe for Duck Soup here it is:
 
Soak 4 oz of dry cat food in water overnight; once softened ,add to food:
One 8 oz can SUSTACAL,ENSURE or other lactose free diet supplement for humans
8 oz of water
optional two scoops KMR kitten weaning formula,KMR or Probalance
 
Place it all in a blender and mix throughly.  Warm one serving to thhe
temperature of baby formula.  Serve 4 fl oz twice a day for maintenance(if
ferret starts to gain to much weight annd is not the objective,thin with
more water).
 
Sustacal must be used within 48 hours if left in refrigerator.  We recommend
using ice-cube trays to freeze the Duck Soup in and pop the cubes out as you
need them.
 
another one:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
One can Sustacal 8 oz this is non dairy
one can water
4 oz dry food - soaked enough to cover and soften completely
OPTIONAL::: electrolyte water { really helps }  Baby food such as chicken
or mashed bananas
 
mixing in a blender works great also and can freeze in ice cube trays also
if you have a seriously ill ferret you can give Sustacal full strength warm
it up alittle.
 
Good luck to all that need it. bye for now Judy
[Posted in FML issue 1818]