Occurrence of Recombinant Canine Coronavirus, Picodicistrovirus, and Circovirus in Red Foxes () Implies Frequent Virus Transmission Events Among Carnivores.

Although their pathogenicity is most often unclear, some canine viruses have been found to infect carnivores other than dogs. This study relies on the surveillance of coronaviruses in 206 saliva and fecal samples of huntable, sympatric canid and mustelid species captured in Hungary, such as the native red fox (), European badger (), golden jackal (), and stone marten (), as well as the recently settled alien raccoon dog (). Metagenomics-based and direct sequence analysis were deployed to determine the genome sequence of coronaviruses identified in two specimens collected from red foxes. Near-complete genome sequences of two canine coronaviruses (CCoVs) were obtained, together with the complete genome sequence of a canine circovirus (CanineCV) and the near-complete genome sequence of a canine picodicistrovirus (CPDV) from one of the samples. These provided the first fox origin CCoV and CPDV sequence data, and the first recorded appearance of the CPDV in Europe. The results suggested that recombination is of great importance in the evolution of CCoV, CanineCV, and CPDV infecting dogs and wild-living carnivores, including the red fox and golden jackal. These are widespread in Central and Southeast Europe, and have large ranges, facilitating transmission of the multihost canine pathogens.