Recently, there have been many reports of pet cats and dogs infected with the COVID-19 virus, and the public’s worry about “pets will spread the virus” has continued to escalate.
On March 31, the Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences published a biomedical preprint bioRxiv entitled “Susceptibility of ferrets, ferrets, cats, dogs, and other livestock” (Susceptibility of ferrets, cats, dogs, and different domestic animals to SARS-coronavirus-2). The results indicate that ferrets and cats are susceptible to SARS-CoV-2 (COVID-19 virus) and can be transmitted among their species, but poultry such as dogs are less likely to contract SARS-CoV-2.
The Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences is one of the national professional institutes affiliated to the Chinese Academy of Agricultural Sciences. It is also a fourth-level laboratory for biosafety and fourth-level animal safety, which is often referred to as the P4 laboratory.
The P4 laboratory is the highest biosafety laboratory in humans, and it is also a large-scale device dedicated to the research of severe infectious diseases, such as Ebola virus, smallpox and the new outbreak of coronavirus, which are generally at this level. Research in the laboratory. According to incomplete statistics, there are more than 50 P4 laboratories worldwide.
SARS-CoV-2 has weak replication ability in dogs, pigs, chickens and ducks, but stronger in ferrets and cats
In this experiment, the researchers used two viruses, one from an environmental sample collected from Wuhan South China Seafood Market (F13-E) and the other from a virus isolated from COVID-19 patients (CTan-H). .
Since ferrets are often used as animal models of human respiratory virus infection, researchers first performed virus infection experiments on this animal.
After four ferrets were injected with high doses of SARS-CoV-2, virus detection revealed that virus replication was found in the ferret’s nasal cavity, soft palate, and tonsils, while in other organs such as the trachea, lungs, heart, spleen, kidney, pancreas The viscera, small intestine, brain and liver are not.
One ferret infected with the two viruses developed fever and loss of appetite on days 10 and 12, respectively. To find out whether the symptoms were caused by the virus’s replication in the lower respiratory tract, the researchers euthanized two ferrets. Except for a small amount of replication found in the nasal cavity, no other organs were detected.
In addition, SARS-CoV-2 antibodies appeared in infected ferrets in the experiment. The antibody titer in ferrets euthanized on day 20 was significantly higher than that in ferrets on day 13.
The study concluded that SARS-CoV-2 can replicate in the upper respiratory tract of ferrets without causing serious illness or death.
Later, researchers conducted experiments on cats in the same way, and found that cats were more susceptible to the virus. A large number of virus replications were detected in cats’ nasal cavity, trachea, tonsils, and lungs. Not only that, the study also found that kittens and kittens were infected with the virus. Adult cats (8 months) were more severe.
In addition, cats can transmit the virus to their peers. In experiments, virus replication was also observed in several unvaccinated cats. The cats were kept in adjacent cages with cats infected with the SARS-CoV-2 virus.
This shows that cats can spread SARS-CoV-2 in the same species through droplets.
After the same experiment was performed on pigs, dogs, chickens, and ducks, no virus replication was detected in them. Moreover, the infected pigs, dogs, chickens and ducks were kept with their uninfected companions, and no virus transmission was found.
All in all, the paper found that cats are susceptible to SARS-CoV-2 and can spread among their peers, while pigs, dogs, ducks, and chickens are less likely to be infected with the virus and will not spread among their peers.