Purevac ferret canine distemper vaccine has shown the lowest rate thus far of allergic reaction and is manufactured by Merial. Last summer I took my furkids on a 240 mile round trip to a veterinarian in central Michigan who uses only Merial Purevac as ferret protection against cd. This vet stated that he has had one reaction to the injection, but that's not bad considering he treats hundreds of ferrets and is the vet for the Lansing, MI ferret shelter. He even kept his clinic open after hours while watching my ferrets to assure their safety. Purevac is not offered by my furkids' local vet. I hope this helps answer the query about safe vaccines for ferrets. Cordially, Greta Hoisington [Posted in FML issue 4319]