Angela, until there is research proving a longer efficacy of IMRAB 3 in ferrets it remains a one year vax in ferrets. How long a vaccine works varies from species to species, and the only way to know is to get the funding for the research to find out how long a given specific vaccine lasts, and it sure would not hurt if there was research top find out what titer numbers in ferrets signify because at this point the levels which actually do indicate protection are unknown. That needs to be done for each of the vaccines because they do vary. For example, one of the rabies vax first tested for ferrets -- which lasts far longer in other species -- lasted all of 6 months in ferrets. It simply didn't give longer protection. It could be useful for you to provide BOTH the info from the AVMA site (which also appears in JAVMA) at http://www.avma.org/pubhlth/rabcont.asp That info is directly from the National Association of State Public Health Veterinarians. I believe the Indiana state public health veterinarian in charge of state rabies policies may (my reference which does not have a printing error affecting those pages is from early 2001) still be either: Dr. Brett Marsh, State Veterinarian, 805 Beechway Drive, Ste. 50, Indianapolis, IN 46224, phone 1-317-227-0300, fax 1-317-227-0330 or (probably far more likely) Dr. James F. Howell, State Public Health Veterinarian and Epidemiologist, Indiana State Dept. of Health, 2 N. Meridian St., 6th Floor, Indianapolis, IN 46204, phone 1-317-233-7272, fax 1-317-233-7805 though this may have been one of the few states in which one office handled some aspects and the other handled others. You could find out which office handles it, verify the timing and then call the vet's office with info on where they can call to see the timing if seeing a copy of it from the AVMA site isn't sufficient. We'd sure all love to be able to give vaccines less often, but until there are studies which show effectiveness AND approval by the USDA and the NASPHV the vet who is issuing the 3 year certificates is making a large error which could place ferrets at risk. Show the vet this: http://www.avma.org/pubhlth/rabcont.asp#part3 and point out that for horse and ferrets IMRAB3 is annually. For dogs, cats, sheep and cattle it is a 3 year vax. [Posted in FML issue 4650]