When I first got my ferrets I brought them in to my normal pet vet because they said they can handle them. I knew I was in trouble when the lady was scared to hold the little buggers for fear of being nipped. This is the same lady that cares for gigantic Danes and has scratches all over her hands and arms from cats.
Then came the vaccinations, she injected my original ferret without bleeding the air out for the needle and before I could "remind her" she uncermoniously injected my ferret in the hind quarters. I took the ferrets and left at that point, stiffing them on the bill and never looked back. After much search I managed to find a highly reccomended vet by a pair of shelters, one which is dedicated to ferrets.
From my understanding, Vets will often reject animals they don't think they can help for fear of being sued...