Coronavirus: new Hong Kong study finds no evidence of dog-to-human Covid-19 transmission

Owners can infect dogs with the coronavirus, but there is no evidence pets have infected people, a new study by researchers at the University of Hong Kong has found. The study, published in the scientific journal Nature on Thursday, looked at 15 dogs living in Hong Kong households with confirmed coronavirus cases, and found just two of the animals were infected. “Viral genetic sequences of viruses from the two dogs were identical to the virus detected in the respective human cases,” the researchers stated in the paper. “The evidence suggests these are instances of human-to-animal transmission of SARS-CoV-2.” The study showed no evidence that dogs can pass the infection to other dogs or people, but said more investigation was needed. But while it found that people who test positive can infect dogs, the study showed the probability of that happening was low. A 17-year-old Pomeranian that belonged to a now-recovered Hong Kong Covid-19 patient was the first dog in the world to test positive for the coronavirus in March. It died after being released from isolation on March 16, which researchers said was likely due to previous underlying diseases. A two-year-old German shepherd living with a Covid-19 patient was also diagnosed with the coronavirus. The study found both dogs were asymptomatic and concluded the German shepherd had not transmitted the infection to a four-year-old mixed-breed dog in the same home. Researchers said the findings had potential implications for the management of mammalian pets owned by people infected by Covid-19, including whether they should be isolated and tested as a precautionary measure. To ensure public and animal health, the Department of Health has strongly advised that mammalian pets, including dogs and cats, living in households with confirmed coronavirus cases be quarantined. That recommendation extends to close contacts of the infected. As of March 27, 15 dogs and seven cats from infected Hong Kong households have been quarantined and tested, researchers said. Coronavirus: Hong Kong confirms a second dog is infected But while the study found no evidence of dogs infecting humans, researchers believed it important to examine any potential role pets might play in the disease’s transmission. While scientists now widely believe Covid-19 originated in bats, it is also thought the virus might pass to humans via an intermediate animal. “Based on experiences with the Sars [severe acute respiratory syndrome] virus, it is likely that intermediate hosts serve to bridge transmission from bats to humans,” the paper said. One leading theory suggests still-unidentified intermediate species came into contact with people in a wild-animal market in the mainland Chinese city of Wuhan, where the outbreak was first detected. Dogs, cats and other mammals are sold for meat in such markets, and stray cats and dogs are known to roam freely. Researchers said those animals should be “tested during investigations into the origin of this virus to determine if they play any role in spillover events.” There have been reports of other pets testing positive for Covid-19. In addition to a cat in Hong Kong and one in Belgium, the US Centres for Disease Control (CDC) has confirmed positive tests for two pet cats in New York City in addition to eight lions and tigers at the Bronx Zoo. Pet owners should always maintain good hygiene practices and under no circumstances should they abandon their pets, the animal welfare authority has said. Animal welfare charity Hong Kong Dog Rescue (HKDR), meanwhile, said it had not received reports of dogs being surrendered over Covid-19 fears, though the Society for the Prevention of Cruelty to Animals (SPCA) said it had one case of a hamster owner giving up their pet for that reason. Pets don’t catch coronavirus easily or spread it to others, Hong Kong vets say “We have seen an increase in initial inquiries, but this hasn’t translated into significantly increased intakes [animals left with the organisation],” said Dr Fiona Woodhouse, director of welfare at the SPCA. In fact, the society said it had seen an increase in people wanting to foster or adopt animals, with 443 adopted compared to 410 in the same period last year. HKDR founder Sally Andersen said the charity had also seen an uptick in people wanting to adopt dogs. “Both in Hong Kong and internationally, there has been a huge increase in dog adoptions, since people have been working from home and the schools have been closed,” Andersen explained. The SPCA also reminded owners infected with Covid-19 to refrain from interacting with their pets. Help us understand what you are interested in so that we can improve SCMP and provide a better experience for you. We would like to invite you to take this five-minute survey on how you engage with SCMP and the news.