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.