Liver Disease. When elevated AST indicates damage to the liver, this damage can come from a variety of different causes, both in the sense of indicating various liver diseases and also in the sense of the diseases being due to various causes.
HEALTH. Ferrets live for 6 to 10 years and during that time they will require regular vaccinations and veterinary check ups to remain in tip top shape. In particular, Ferrets are prone to canine distemper and heartworm, so regular preventative treatments like Heartguard should be used.
Ferrets can be litter trained. Although it may not be 100% all the time, they should go in it most of the time. As long as they're trained, they won't pee everywhere. Ferrets are illegal in the states of California and Hawaii and in New York City that I know of.