During 2012-2017, we collected throat swabs from dogs in China to characterize canine influenza virus (CIV) A(H3N2) isolates. A new antigenically and genetically distinct CIV H3N2 clade possessing mutations associated with mammalian adaptation emerged in 2016 and replaced previously circulating strains. This clade probably poses a risk for zoonotic infection.
Keywords: China; H3N2; PB2; adaptation; antigenicity; canine influenza; dogs; evolution; influenza; influenza A virus; mammalian adaptations; respiratory infections; serology; surveillance; viruses; zoonoses.