Infection of eight mesocarnivores in New Hampshire and Vermont with a distinct clade of canine distemper virus in 2016–2017

Three fishers ( Martes pennanti), 2 gray foxes ( Urocyon cinereoargenteus), 1 mink ( Neovison vison), 1 skunk ( Mephitis mephitis), and 1 raccoon ( Procyon lotor), from Vermont and New Hampshire, had lesions on autopsy consistent with canine distemper virus (CDV) infections diagnosed in a 12-mo period in 2016–2017. Lesions of CDV infection were most commonly noted in the lungs (8 of 8 animals), urothelium (5 of 8), biliary tract (5 of 8), gastrointestinal tract (4 of 7), and brain (4 of 6). Splenic lesions were seen in 3 animals. The diagnosis was confirmed via immunohistochemistry and virus isolation. Viral genotyping indicated that all 8 animals were infected with a distinct clade of CDV that has only been reported in wildlife in New England, and this clade of viruses is distinct from vaccine strains. During the 12 mo when these cases occurred, no other CDV clade was identified in any other wildlife or domesticated animal submitted from the 2 states.