Emerging variants of canine enteric coronavirus associated with seasonal outbreaks of severe canine gastroenteric disease

Canine enteric coronavirus (CECoV) variants have an emerging role in severe outbreaks of canine gastroenteritis. Here we used syndromic health data from a sentinel network of UK veterinary practices to identify an outbreak of severe canine gastroenteritis. Affected dogs frequently presented with vomiting, diarrhoea and inappetence. Data from sentinel diagnostic laboratories showed similar seasonal increases in CECoV diagnosis. Membrane glycoprotein (M) gene sequence analysis implied wide geographical circulation of a new CECoV variant. Whole genome sequencing suggested the main circulating 2022 variant was most closely related to one previously identified in 2020 with additional spike gene recombination; all variants were unrelated to CECoV-like viruses recently associated with human respiratory disease. Identifying factors that drive population-level evolution, and its implications for host protection and virulence, will be important to understand the emerging role of CECoV variants in canine and human health, and may act as a model for coronavirus population adaptation more widely.