Cats highly susceptible to COVID-19, can spread to other felines

Chinese scientists have found that cats are highly susceptible to the novel coronavirus and may spread it to other cats via respiratory droplets, like humans. Ferrets also were found to be highly susceptible, though less so for dogs, pigs and poultry, according to a new study.

While the findings are intriguing for locating intermediate hosts for the virus, scientists said it is still unclear whether the felines can spread the virus to people, so pet owners don't need to panic yet.

The study was done by scientists at the Harbin Veterinary Research Institute, China's top institution for studying animal viruses. It was published on preprint server bioRxiv on Tuesday, meaning it has not been peer reviewed and its findings are up for debate.

The results were based on lab experiments on a small number of animals deliberately given high doses of the virus, and thus do not represent real-life interactions between people and their pets.

Pet owners around the world recently grew anxious when reports of a cat in Belgium and two dogs in Hong Kong had contracted the virus. Since these pets are in close contact with humans, it is crucial to understand their susceptibility to SARS-CoV-2, the virus that causes COVID-19, the study's authors said.

To probe this question, researchers introduced the virus into the noses of five domestic cats. Two of the test animals were later euthanized, and scientists found the virus's genetic material, as well as infectious viral particles in their upper respiratory tracts, suggesting the virus could replicate in these animals.

The remaining three cats were put into cages adjacent to healthy felines, and the team later discovered that one of these exposed cats had contracted the virus from droplets breathed out by the sick cats. They also found antibodies against COVID-19 in all four of the infected cats, and they displayed no obvious symptoms.

As for dogs, the scientists introduced the virus to five young beagles and housed them with two healthy ones. Traces of the virus were detected in rectal swabs in three virus-inoculated dogs, but no live infectious virus was detected.

Moreover, there was no apparent transmission to the two healthy dogs. The data suggest that dogs have low susceptibility to the virus compared to ferrets or cats.

The study's authors also found that ferrets are highly susceptible to COVID-19, making them a suitable animal model for testing potential vaccines and drugs. Ferrets have already been widely used as animal models for the study of human respiratory viruses, such as influenza.

The authors concluded that further research and surveillance for the coronavirus in cats are needed to contain and eliminate COVID-19 in humans.

The US Centers for Disease Control and Prevention recommends that people with COVID-19 limit contact with their pets to avoid getting their animal companions infected.