therapy pet?

Question
My ferret has proven that she could pass an examination by traveling to a senior center, park, and elementary school, but her presence is highly restricted due being uncertified. I have looked into certifying my ferret as a therapy pet; however, it appears everyone considers ferrets "vicious and unpredictable" (NY Health Department) or "wild and exotic" (DeltaSociety). I full-heartedly believe that any creature with a tame temperament should be given a fair shot at the certification tests without prejudice to species. By reading stories about ferrets getting certified, I know that certification is not impossible. Can you refer me to an organization that certifies ferrets or give me some advice as to why "all animal" certification organizations exclude select "exotic" animals such as ferrets which have proven to be a tamer species throughout their history with humanity than dogs or cats?

Answer
You have many good points.  I am working with Delta Society currently for my dog and cat and am frustrated that they will work with miniature horses but not reptiles or ferrets which I also feel make great animals to handle etc.  My understanding is that ferrets (and other exotics) are sometimes able to be used and/or certified by local organizations like a humane society but I am unaware of a national certification program.  If you find one or hear about one, please let me know.