gray fox with canine distemper

Canine Distemper Virus in Northeastern Wildlife: Implications for Conservation Efforts

Canine distemper virus (CDV) is a highly contagious virus that affects both domestic and wild canids. In recent years, there have been reports of CDV affecting a variety of wildlife species in the northeastern United States. This raises concerns about the potential impact of the virus on wildlife populations and conservation efforts in the region.

Distinct Clade of CDV in Northeastern Wildlife:

In 2016-2017, several wildlife species including two fishers, two gray foxes, and a striped skunk, were diagnosed with CDV by pathologists at the NHVDL. Researchers from New Hampshire Veterinary Diagnostic Lab, Cornell University, Vermont Department of Fish and Wildlife, and New Hampshire Fish and Game Department determined that all isolates from these animals were part of a distinct clade of CDV that has only been reported in this study and one single raccoon not associated with any other publication or report. This work was published in the Journal of Veterinary Diagnostic Investigation.

Impact on Wildlife Populations:

CDV can reduce local population sizes, but it 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 endpoint. These factors make it likely that CDV is underreported, and its impacts on populations are incompletely understood. CDV affecting fishers, which are a valuable furbearer species, raises concerns about the potential impact of the virus on their populations. Their populations are increasing in some areas (NY) and declining in others (NH). 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.

Diagnostic Efforts:

To better understand the impact of CDV on wildlife populations in the region, ongoing efforts are being made to characterize the virus in the population and perform diagnostics in any overtly ill animals. A small investigation of five animals from Berlin, NH, that were rabies negative but noted to be ill/neurologic were submitted by NH F&G and all were found to be infected by the same distinct clade of CDV. At the same time, samples of tissue from 40 carcasses from the 2018 VT fisher harvest were tested for CDV, with one animal having the virus, again in this distinct clade.


The discovery of a distinct clade of CDV affecting wildlife in the northeastern United States highlights the importance of continued diagnostic efforts to better understand the impact of the virus on wildlife populations in the region. These efforts are critical to informing conservation strategies and protecting vulnerable species from potential threats.

Learn more about various diseases impacting wildlife here.