Serosurveillance and Parasite Survey of Swift Fox (Vulpes velox) from Southeastern Wyoming, USA.

Abstract

The swift fox (Vulpes velox) is a small canid species occupying mixed and short-grass prairie ecosystems across western North America. Populations have declined across a large portion of their historical habitat distribution, mainly due to anthropogenic influences. Although some populations appear to be rebounding, the swift fox is classified as a species of greatest conservation need in Wyoming, USA, due to threats from predation, vehicular collisions, and habitat alterations that increase potential contact with humans and domestic animals. This potential contact with other species puts swift foxes at risk from infectious disease transmission, potentially resulting in morbidity or mortality. There are few published studies about disease seroprevalence and presence of parasites from swift foxes within Wyoming. Serum samples (n=103) and fecal samples (n=113) from live swift foxes were opportunistically collected from southeastern Wyoming (2009 and 2020-24) and submitted for testing. Serum samples were assessed for antibodies using an indirect fluorescent antibody test, canine parvovirus (CPV), and virus neutralization tests, canine distemper virus (CDV) and canine adenovirus (CAV). Fecal samples were tested using a standard fecal float and a real-time PCR for Echinococcus spp. and Echinococcus multilocularis. Not all samples could be tested for every assay. Overall, 58 (73%; n=80) foxes were seropositive for CPV, 5 (19%; n=27) for CAV, and 1 (2%; n=53) for CDV. Toxascaris leonina was the most commonly detected (31%; n=44) gastrointestinal parasite, and Echinococcus spp. was detected in one individual (0.9%; n=113). These results reveal previously unidentified levels of seroprevalence and lack of difference between age and sex in this species. Continued exploration and surveillance is needed to assist in determining associated morbidity and mortality and to identify risk factors (e.g., domestic canid, other wild canid comingling) contributing to disease transmission within this population.