Lucie explained how she found that her ferret could open the sliding screen door of her sliding glass door. With warm weather coming, ferret owners should also be aware that most screens are now made of a fiber glass material. A ferret's claws will go through that like a hot knife through butter. The screen might as well not be there. We had to replace all of the screen on our screen porch with metal screen. I know that they can get through that too, but it does take longer and does make a racket. So far <looking for wood to knock on> they haven't tried digging through the metal screen. Live Virus Distemper Vaccine - not a problem unless . . . . Ferret distemper vaccinations normally use a modified live virus to create the immunity. I think the poster yesterday may have been confusing the use of modified live RABIES virus which is dangerous and may cause rabies in ferrets. The real danger is in using a canine distemper vaccine developed in ferret cell cultures. THAT does constitute a very significant risk of distemper infection in a ferret. FERRVAC, the only USDA approved CDV for ferrets, is a modified live virus vaccine but is not cultured in ferret cells. Dick B. [Posted in FML issue 2214]