We use a 1/2 dose of Vanguard DHPi for vaccinating ferrets. I think (but I haven't the ref book here to check) that Vanguard is the only one that does not explicitly state in the data sheet that it is *not* safe for use in ferrets - i.e. all the others definitely do state they should not be used. I have used it in a number of ferrets without problems. However, I don't know if it is protective for distemper, as we have almost no distemper in dogs in this area anyway. We checked with whoever makes Vanguard (I know I should know, but I have children buzzing round and can't think) and I think they said it was ok but had no data. I hope this is of some help. Alison the vet in England, 3 ferrets. [Posted in FML issue 3608]