Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) descriptions of infection and transmission have been increasing in companion animals in the past year. Although canine susceptibility is generally considered low, their role in the COVID-19 disease cycle remains unknown. In this study, we detected and sequenced a delta variant (AY.3) from a 12-year-old Collie living with owners that previously tested positive for SARS-CoV-2. It is unclear if the dogs' symptoms were related to SARS-CoV-2 infection or underlying conditions. The whole genome sequence obtained from the dog sample had several unique consensus level changes not previously identified in a SARS-CoV-2 genome that may play a role in the rapid adaptation from humans to dogs. Within the spike coding region, 5/7 of the subconsensus variants identified in the dog sequence were also identified in the closest in-house human reference case. Taken together, the whole genome sequence, and phylogenetic and subconsensus variant analyses indicate the virus infecting the animal originated from a local outbreak cluster. The results of these analyses emphasize the importance of rapid detection and characterization of SARS-CoV-2 variants of concern in companion animals.
Keywords: AY.3; COVID-19; SARS-CoV-2; canine; delta variant; dog.