Vaccine-Induced Canine Distemper in European Mink, Mustela lutreola

This report describes vaccine-induced canine distemper virus (CDV) infection in four European mink (Mustela lutreola) induced by the administration of a multivalent, avian-origin vaccine. Clinical signs consisting of seizures, ataxia, facial twitching, oculonasal discharge, hyperkeratosis of footpads, and anorexia developed 16-20 days postvaccination. Conjunctival smears from one animal were positive for CDV antigen by direct fluorescent antibody testing, confirming the clinical diagnosis. The four mink died 16-26 days postvaccination. Gross and microscopic lesions that were diagnostic for CDV infection included interstitial pneumonia, lymphoid depletion, nonsuppurative encephalitis, and dermatitis. Vaccine-strain virus was isolated from tissues of three animals. Cases of vaccine-induced distemper in mustelids using avian-origin vaccine have seldom been reported.