Ferretone and Linatone
Ferretone and Linatone are two popular vitamin supplements. They are also a common treat, since nearly all ferret loves them. These products can be used interchangeably, although their exact composition is a bit different. Both contain vitamin A, which can be harmful or even fatal in excess, however it takes a whole lot more than you'd ever give your ferret. Still, some people prefer to dilute them 50/50 with olive or vegetable oil (not mineral oil), which is fine. Also, as with hairball remedies, too much Ferretone or Linatone can give your ferrets loose stools. Do not supplement more than a few drops a day, or as recommended by your Vet.
Hairball remedies
Many people give their ferrets a small amount of a cat hairball remedy such as Kittymalt or Petromalt on a regular basis. These products can help them pass foreign objects which fuzzies seem to love (rubber bands, styrofoam, etc