How long has the bump been there? Our ferret has had her bump for almost a year...very unlikely to be a vaccine reaction. It is compact and not malleable--she periodically scratches it and makes a bit of a mess of it. Our vet believes it is a benign mast cell tumor that should be removed (primarily because it bothers her) and tested (to ease our minds). I'll let you know what the results are. Jennifer Skeem, MS Department of Psychology University of Utah SLC, UT 84112 (801) 486-4518 [Posted in FML issue 1839]