SARS-CoV-2 delta variant infection in domestic dogs and cats, Thailand

In June–September 2021, we investigated severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections in domestic dogs and cats (n = 225) in Bangkok and the vicinities, Thailand. SARS-CoV-2 was detected in a dog and a cat from COVID-19 positive households. Whole genome sequence analysis identified SARS-CoV-2 delta variant of concern (B.1.617.2). Phylogenetic analysis showed that SARS-CoV-2 isolated from dog and cat were grouped into sublineage AY.30 and AY.85, respectively. Antibodies against SARS-CoV-2 could be detected in both dog (day 9) and cat (day 14) after viral RNA detection. This study raises awareness on spill-over of variant of concern in domestic animals due to human-animal interface. Thus, surveillance of SARS-CoV-2 in domestic pets should be routinely conducted.