I have had ferrets since 1997 and up until last summer never had any reactions to vaccines. I should also add that up until that time I wasnt using the right distemper vaccine. I like to think of my ferret ownership as a continuing "education in progress" and last year did much research and reading when many of my babies were sick. I requested ferret vaccines and my vet ordered them for me. I asked her why she didnt like the ferret vaccine and she said she had many reactions to them (in the ferrets). So interestingly enough I have had three reactions in two ferrets since switching to the Fervac. I was very lucky that in the six years of my ignorance I didnt have one single reaction to the rabies and distemper and they were given at the same time. I now am more informed and give only one at a time and stay at the vets to be sure all will be ok. When my "Fervac" supply is gone I will be changing to the Merial ferret distemper and see if that helps. My education continues.................. Rita B. [Posted in FML issue 4447]