www.cachins.org is a great website for medical info.
Here is an excerpt from their site:
"
We have only had 3 diabetic chins known to us, and none of them have had seizures do to hypoglycemia, [low blood sugar] although this is not uncommon in ferrets, and has been seen in chins. The main symptom of this type of seizure is when the animal has been active and then collapses. The collapse is sudden and the animal is limp. Try to get a sweet product in them."