MOSCOW, May 14. /TASS/. Hong Kong medics and vets discovered SARS-CoV-2 antibodies in two dogs, whose owners had contracted the COVID-19 disease, and also extracted a "live" virus culture from one of the pets’ bodies for the first time. The results of their research have been published in the Nature journal.
"Rhinolophid bats are considered a likely reservoir of the precursor of SARS-CoV-2. However, based on experiences with SARS virus, it is likely that intermediate hosts serve to bridge transmission from bats to humans. Dogs, other canids, and felids can be sold in or found in the vicinity of wild-game animal markets, the presumed source for the initial zoonotic spill-over of SARS-CoV-2. They should be tested during investigations into the origin of this virus to determine if they play any role in spillover events," the scientists write.
The SARS-CoV-2 coronavirus, the reason behind the COVID-19 disease, can penetrate not only human bodies, but bodies of many other mammals, as well. Recent experiments of biologists and observations of veterinarians indicate that rhesus macaques, ferrets and cats are affected by the infection almost as severely as humans are.
Additionally, over the past two months, researchers have registered several cases of coronavirus infection in domestic dogs, contracted, presumably, from their infected owners. Such statements still cause a lot of arguments among scientists: many of whom point out that the structure of the ACE2 protein, which the virus uses to penetrate target organisms, differs significantly between humans and dogs.
Four-legged victims of the coronavirus
A group of biologists from the Hong Kong University, led by prof. Malik Peiris, obtained the first unambiguous evidence that the coronavirus infection can penetrate dog’s bodies, also discovering that the infection in dogs happens without symptoms. They have come to this conclusion after researching blood and nasal discharge samples, harvested from 15 pets, whose owners contracted the infection in February or March.
Traces of the virus — antibodies and fragments of its RNA — were registered in two dogs. One pet died two days after admittance to the clinic, while the second one has recovered.
The scientists managed to extract full-fledged virus particles from samples harvested from the deceased dog, decode their RNA and confirm that the "canine" coronavirus was quite viable. Comparison of its genome with other coronavirus strains revealed that it was closely related to the coronavirus variations that spread across Hong Kong during the first days of the COVID-19 outbreak in China.
Interestingly, owners of the second dog also have another dog, which did not contract the disease. This might indicate that the coronavirus transmits from one dog to another much less often than between cats or humans.
Still, the very fact of the virus infection and propagation in the canine bodies indicates that it is possible that dogs, not bats or pangolins, were the initial source of the infection, since dog meat could be bought at exotic meat markets in China, the researchers believe.