Thomas H C THC Sit, Christopher J CJ Brackman, Sin Ming SM Ip, Karina W S KWS Tam, Pierra Y T PYT Law, Esther M W EMW To, Veronica Y T VYT Yu, Leslie D LD Sims, Dominic N C DNC Tsang, Daniel K W DKW Chu, Ranawaka A P M RAPM Perera, Leo L M LLM Poon, Malik M Peiris
SARS-CoV-2 emerged in Wuhan in December 2019 and caused the pandemic respiratory disease, COVID-19. In 2003, the closely related SARS-CoV had been detected in domestic cats and a dog. However, little is known about the susceptibility of domestic pet mammals to SARS-CoV-2. Two out of fifteen dogs from households with confirmed human cases of COVID-19 in Hong Kong SAR were found to be infected using quantitative RT-PCR, serology, sequencing the viral genome, and in one dog, virus isolation. SARS-CoV-2 RNA was detected in a 17-year-old neutered male Pomeranian from five nasal swabs collected over a 13-day period. A 2.5-year-old male German Shepherd dog had SARS CoV-2 RNA on two occasions and virus was isolated from nasal and oral swabs. Both dogs had antibody responses detected using plaque reduction neutralization assays. Viral genetic sequences of viruses from the two dogs were identical to the virus detected in the respective human cases. The animals remained asymptomatic during quarantine. The evidence suggests that these are instances of human-to-animal transmission of SARS-CoV-2. It is unclear whether infected dogs can transmit the virus to other animals or back to humans.