LAUSR

Abstract: Black-footed ferrets (Mustela nigripes) are an endangered species in North America that are highly sensitive to canine distemper virus (CDV) infections and any exposure could be devastating to species recovery. The U.S. Fish and Wildlife Service recovery program has safely used a recombinant DNA (rDNA) canarypox-vectored CDV vaccine, Purevax® Ferret Distemper (PFD), to vaccinate black-footed ferrets. Because of a PFD shortage in 2015, an rDNA vaccine labeled for use in dogs, Recombitek® CDV (rCDV), was chosen to vaccinate black-footed ferrets. Our goal was to compare the serum neutralizing (SN) titers after vaccination of 17 captive and 18 wild black-footed ferrets with rCDV or PFD, respectively, considering ≥1:128 as a protective titer. Both vaccines produced comparable 1 yr postvaccination protective titers in captive and wild black-footed ferrets. In wild black-footed ferrets, one PFD vaccination produced SN titers similar to two PFD vaccinations at 1 yr postvaccination. One year after vaccination with rCDV, SN titers in captive black-footed ferrets were higher than in wild ferrets. These results indicate rCDV may be an effective alternative CDV vaccine in captive black-footed ferrets and PFD should be prioritized for wild ferrets because one dose was effective for animals that can be difficult to recapture.