show Abstracthide AbstractCanine respiratory coronavirus (CRCoV) has been identified as a causative agent of canine infectious respiratory disease (CIRD), an upper respiratory infection affecting dogs. The epidemiology is current opaque, with an unclear understanding of global prevalence, pathology, and genetic characteristics In this study, Swedish privately privately-owned dogs with characteristic signs of CIRD (n=108) were screened for CRCoV and 13 positive samples further sequenced. Sequenced Swedish CRCoV isolates were highly similar despite being isolated from dogs living in geographically distant locations and across 3 years (2013-2015). This is due to a single introduction into Swedish dogs in approximately 2010, as inferred by time structured phylogeny. Unlike other CRCoV viruses, there was no evidence of recombination in Swedish CRCoVs, further supporting a single introduction. Finally, there are low levels of polymorphisms, representing quasispecies in the S genes. Overall, we demonstrate that there is little diversity of CRCoV which is endemic in Swedish dogs.