Just wanted to say that I have a ferret, her name is Lilly. :) Whipple has given some excellent advice. Another great forum is Everything Ferret, I am a moderator there. We are like family there.
Whipple is 100% correct in that ferrets are obligate carnivores and should not be given sugar or anything other than meat-related food and treats. They CANNOT digest anything else, that is how their bodies are made. Too much sugar can lead to multiple types of cancer. The ferret will then need to be on medication for the rest of its life. I have had a ferret die from insulinoma and another one died of lymphoma and it is not pretty or cheap. Medications and surgeries are expensive. So my advice is to not feed anything other than meat. I mean, what's the point? If you had a child and all they wanted to eat was sugar, would you let them? No, because it isn't good for them. You have to treat them like children in that way. A high protein food low in fillers is the best thing for them aside from raw or natural diet. Some cat food out there are really good for them, like Innova Evo. You just have to read ingredients.
They are a high-maintenance pet, so anyone thinking of getting one should be able to put in at least 2 hours a day to playing with them or at least being able to supervise their playtime. And you still have to pay for shots, food, litter, etc. They aren't cheap, but then again neither are horses! They are definitely worth it though. :)
Mommy to Minnie, Lilly, and Tanner.