Ferrets could help in the race for treatments and vaccines for coronavirus, researchers say.

Scientists looking for animal models for Covid-19 infections to support urgent development of drugs found that it replicates poorly in dogs, pigs, chickens and ducks but efficiently in ferrets and cats.

They say their findings point to ferrets as a candidate animal model for evaluating antiviral drugs or vaccines.

Jianzhong Shi of State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, and colleagues, evaluated the susceptibility of different model laboratory animals to coronavirus.

They also looked at companion and domestic animals.

All experiments were performed in biosafety level 4 facilities, following protocols for animal welfare.

The fact that SARS-CoV-2 replicates efficiently in the upper respiratory tract of ferrets makes them a candidate animal model for evaluating antiviral drugs or vaccine candidates

The researchers delivered viral samples to the animals through the nose or via the trachea (for ferrets), and then measured the extent of replication in various tissue sites.

They found that Covid-19 replicated poorly in all the animals but the ferrets and cats.

In ferrets and older cats, it replicated in the upper respiratory tract, not the lung.

In studies of airborne transmission, they found it was poorly transmissible in ferrets, but it transmitted via air in cats, particularly in juvenile cats.

Researchers say the fact that the virus replicates efficiently in the upper respiratory tract of ferrets makes them a candidate for evaluating antiviral drugs or vaccine candidates.

In the study published in the Science journal, the authors write: “We found that SARS-CoV-2 replicates poorly in dogs, pigs, chickens, and ducks, but ferrets and cats are permissive to infection.

“We found experimentally that cats are susceptible to airborne infection.

“Our study provides important insights into the animal models for SARS-CoV-2 and animal management for Covid-19 control.”

They add: “The fact that SARS-CoV-2 replicates efficiently in the upper respiratory tract of ferrets makes them a candidate animal model for evaluating antiviral drugs or vaccine candidates against Covid-19.”