Fatal vaccine-induced canine distemper virus infection in black-footed ferrets

Four black-footed ferrets that were live-trapped in South Dakota and transported to the Patuxent Wildlife Research Center died within 21 days after vaccination with modified live canine distemper virus. Immunofluorescence, European ferret inoculation, virus isolation attempts, and serum-neutralization tests indicated insufficient attenuation of the vaccine for this species.