Tigers and Lions, but Probably Not Dogs

Many questions remain about which animals are susceptible to Covid-19

A four-year-old Malayan tiger at New York City’s Bronx Zoo has tested positive for the coronavirus, AP reported yesterday. The tiger, named Nadia, had exhibited a dry cough since March 27, and a group of six other tigers and lions with suspected infections were wheezing and had lowered appetites. Zoo officials believe that Nadia and the other cats were infected by one staff member who was infected, but asymptomatic.

The discovery complicates what little we know about Covid-19 and its ability to infect animals. We do know that it’s a zoonotic (animal-to-human) disease — one that originated in an animal host (likely bats) and developed the ability to spread to humans. But in addition to Nadia’s case, there’s only a handful of anecdotal evidence showing that human-to-animal transmission is possible: a housecat in Belgium, and a pomeranian and a German shepherd in Hong Kong, all suspected to have caught the virus from their owners. Some scientists have raised concerns that great apes, who share 98% of their DNA with humans, are also susceptible, but no cases have been documented yet.

There’s some evidence that Covid-19 infects some animals but not others. In a non-peer-reviewed study posted to the open-source journal bioRxiv on March 31, researchers from the Harbin Veterinary Research Institute in China pointed to the susceptibility of cats. “We found that SARS-CoV-2 replicates…