Make him what my vet calls chicken soup. It is about all my Sebastian will eat.

1 jar of chicken broth baby food
1 can of ensure (I use vanilla, high protein)
whipping cream
ferretone

Empty jar of baby food into container. Fill jar with whip cream, shake, empty into container. Mix. Add can of ensure. Add a good squirt of ferretone. Mix well. Keep refridgerated.

Put about 4 tablespoons into a small ferret sized bowl. Warm in microwave for 8-10 seconds. Give bowl to ferret. You might have to stick his nose into the bowl at first, he will likely shrinkle up his nose at first, but if you can get him to eat this it is very, very good for him and will help him put weight on. Sebastian gets his "soup" twice a day. In each bowl I have the soup and all the meds he needs each day.

Good luck, I hope he takes the soup.