Low Titers of Canine Distemper Virus Antibody in Wild Fishers (Martes pennanti) in the Eastern USA.

Canine distemper virus (CDV) infects species in the order Carnivora. Members of the family Mustelidae are among the species most susceptible to CDV and have a high mortality rate after infection. Assessing an animal's pathogen or disease load prior to any reintroduction project is important to help protect the animal being reintroduced, as well as the wildlife and livestock in the area of relocation. We screened 58 fishers for CDV antibody prior to their release into Pennsylvania, US, as part of a reintroduction program. Five of the 58 (9%) fishers had a weak-positive reaction for CDV antibody at a dilution of 1:16. None of the fishers exhibited any clinical sign of canine distemper while being held prior to release.

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

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.

Efficacy of two canine distemper vaccines in wild Nearctic river otters (Lontra canadensis).

Canine distemper virus (CDV), a contagious morbillivirus, infects families in the order Carnivora, including Nearctic river otters (Lontra canadensis). As a preventative measure, vaccinations against CDV are frequently given to mustelids in captive environments. The Pennsylvania River Otter Reintroduction Project (PRORP) used wild-caught river otters to evaluate the efficacy and need for vaccinations against CDV as part of any reintroduction project. The objectives of this study were to: 1) evaluate the prevalence of exposure to CDV in wild river otters, 2) determine the immunologic response of river otters (i.e., seroconversion) after vaccination with a single (primary) vaccine dose compared to a second (booster) dose of Galaxy-D, a modified live-virus canine distemper (CD) vaccine (MLV CDV), and 3) determine the immunologic response after being vaccinated with a primary vaccination compared to a booster dose of Fervac-D, an MLV CDV. River otters were injected subcutaneously in the nape of the neck with their designated vaccine. Timeframes for collection of blood samples and/or injection of booster vaccines varied depending on the parameters of PRORP. Ten of the 22 river otters had positive prevaccination titer levels to CD. Both vaccines, Galaxy-D and Fervac-D, produced sufficient seroconversion or rise of titer levels (86% and 57%, respectively) to recommend the use of vaccines in wild river otters. Future studies are recommended to evaluate currently produced CD vaccines. Future research should also focus on the number of days required between administration of primary and booster vaccines to achieve sufficient immune response. If only a primary dose is required, then hard-release reintroduction projects for river otters could be recommended. If primary and booster vaccines are required then soft-release reintroduction projects should be recommended. Soft-release projects should include captive management periods that allow for appropriate vaccination intervals and boosters needed to maximize the probability of protection against CDV.