I've been to Vetco once for shots for my ferrets.  They didn't use the same
rabies vaccine (Rhone-Merieux) as my regular vet.  Instead, they used a
rabies vaccine that they also used for dogs.  This made me nervous, because
it is critical that rabies vaccines for ferrets not be cultured in ferret
tissue.  However, a rabies vaccine cultured in ferret tissue COULD be used
for dogs.  All it takes is one mistake ... a change in the kind of vaccines
supplied, a failure to check the label, an automatic grab-it-off-the-shelf
response.  The shots were OK; I just didn't want to risk it after that.
[Posted in FML issue 2229]