My vet advises 3 hours max for fasting a ferret with possible insulinoma. The fasting is harder on them because of their already low blood glucose levels. If your ferret is sleeping before you take away his food, he may be fasting longer anyway. If you start 3 hours before the appointment, then it will still be under 4 hours even if the vet is running late. The secretary probably just gave you their standard cat and dog answer. Blessings Judith -- * * * Support Our Shelters * * * http://www.SupportOurShelters.org [Posted in FML issue 3780]