Utility of two modified-live virus canine distemper vaccines in wild-caught fishers (Martes pennanti)

Abstract

Background: Canine distemper virus (CDV) infects families in the order Carnivora. As a preventive measure, vaccinations against CDV are frequently given to mustelids in captive environments.Objectives: Our objectives were to compare the utility between two modified-live virus canine distemper vaccines (MLV CDV's), Fervac-D® (no longer manufactured) and Galaxy-D® (now manufactured by MSD Animal Health as part of a multivalent vaccine), in developing an immune response in wild-caught fishers.Animals and methods: The Pennsylvania Fisher Reintroduction Project (PFRP) used 14 wild-caught fishers during one year of the project to evaluate the utility of vaccinations against CDV as part of any reintroduction project. Fishers were injected subcutaneously in the nape of the neck with their designated vaccine.Results: Fervac-D® did not effectively stimulate development of a serologic antibody response, whereas Galaxy-D® had adequate seroconversion or rise of titer levels to suggest that the general use of MLV CDV may be suitable in fishers pending further studies.Conclusion: We recommend that future studies be conducted, evaluating the use of currently produced vaccines in fishers. Future research should also focus on the length of days required between administration of primary and booster vaccines to achieve sufficient immune response.Clinical importance: If only primary doses are required, then hard-release reintroduction projects for fishers could be recommended. If primary and booster vaccines are required then soft-release reintroduction projects should be recommended that include captive management periods, allowing for appropriate vaccination intervals needed to maximize the probability of protection against CDV.