Fisher & Distemper Virus in the Northeast
Beginning in 2016, New Hampshire state biologists received increased calls of sick or deceased fox and fisher turning up in suburban yards. What was originally believed to be isolated cases of illness or rabies, have now been confirmed as an outbreak of distemper virus. In cooperation with the Northeast Wildlife Disease Coop, NH Fish and Game biologists have called upon local trappers to assist with turn-in of trapped Fisher carcasses for tissue extraction to further study the extent and diversity of the distemper issue.
Trapped carcasses are traditionally regarded as the preferred form of submission due to trapping being a “controlled” method of take. Road-killed specimens, animals showing symptomatic traits, or animals that have been shot via traditional hunting seasons may exhibit excessive tissue damage and specimen timeline uncertainty. As always, NH trappers’ pledge to aid in conservation of furbearer species and work as the “boots on the ground” to monitor populations in the field has been fulfilled.
Additionally, as of April 2018, NH trappers participated with West Virginia's research. Tissue samples from 13 fisher trapped during NH's 2017 fur season were furnished to West Virginia University for genetic comparison of each state's fisher population.
The project is ongoing in various forms. NH trappers continue today, each fur trapping season since 2017, to assist with furnishing of tissue samples from harvested individuals as needed.
A female fisher taken during the month-long winter season in southern New Hampshire. Fisher in the Northeast are taken outside of sensitive times of the year - such as during birthing and the rearing of young. (Photo | Furbearer Conservation™)
From The Northeast Wildlife Disease Coop:
"In March of 2016, two fishers, two gray foxes, and a striped skunk, found in Vermont and New Hampshire, were diagnosed with canine distemper virus (CDV). Sporadic mortality was also reported in a variety of mammals in various locations in the two states, suggesting that CDV may have affected these animals as well. CDV can reduce local population sizes, but is not known to significantly affect populations on a larger geographic scale. However, the magnitude, frequency, and distribution of CDV epizootics are often unknown because of limited response capacity, and because rabies is often the diagnostic end point. These factors make it likely that CDV is underreported and that its impacts on populations are incompletely understood. NWDC participants, New Hampshire Veterinary Diagnostic Lab and Cornell University, are collaborating with biologists from Vermont Department of Fish and Wildlife and New Hampshire Fish and Game Department, and researcher Rebecca Wilkes (University of Georgia), to determe which strains of CDV are circulating in mammals in the Northeast. Fishers, which were affected by the epizootic, are a valuable furbearer species with populations that are increasing in some areas (NY) and declining in others (NH). CDV can also infect domestic species, and this research project will help determine whether CDV found in fishers is unique to the species, spillover from other wildlife species, or closely related to CDV in domestic animals."