It is a common assumption that if your ferret doesn't go outside then he does not need yearly vaccinations. Such a belief could very well prove fatal for your ferret. Canine Distemper and Rabies can affect ferrets that never set foot outdoors.
Canine Distemper (CD) is an airborne disease, meaning that your ferret doesn't need to come in contact with an infected dog in order to get it. CD can be brought into your house on your clothing or shoes. Unfortunately, there is a 100% mortality rate for unvaccinated ferrets that come into contact and contract Canine Distemper. However, Merial, an animal health company, has created PureVax-D, a USDA approved vaccine meant to combat CD with relatively low reaction rates. Pet store ferrets, and some ferrets from breeders, are generally given their first CD vaccine before being purchased; however, it is important to inquire about specific vaccine policies to be sure. They will then need 2 more booster vaccines, and are vaccinated yearly thereafter.
Rabies in ferrets has a relatively low number of documented cases in the United States(less than 20 since the 1950s), and infection worldwide is fairly rare. Still, it is vital to vaccinate your ferret against rabies. First and foremost, a rabies vaccine will prevent against infection, which though slim, can still happen. Furthermore, it is essential to have proper rabies vaccination certification information necessary should your ferret ever bite someone. Pet owners that find themselves in this scenario without the proper paperwork and vaccination history may find that their ferret (or any pet) seized by the state, quarantined, or worse, euthanized. The rabies vaccine also needs to be given yearly, although due to the small size of ferrets, the rabies and Canine Distemper vaccines can't be given at the same time.
Vaccinating your ferret is a small, but very important, part of your pet's health care routine. By providing your ferret with the proper vaccines, you are ensuring that he or she, and those around him, are getting the best possible care and living the longest life possible.