Four lions at Barcelona Zoo have tested positive for COVID-19, veterinary authorities said on Tuesday, according to a Reuters report.

Three females named Zala, Nima and Run Run and Kiumbe, a male, were tested after keepers noticed they showed slight symptoms of coronavirus. Two staff at the zoo also tested positive for
coronavirus, the authorities said, after the outbreak was first detected last month. The authorities are reported to be investigating how the lions became infected.

Earlier in April five tigers and three lions at the Bronx Zoo in New York City had tested positive for the virus that causes COVID-19. The big cats were suspected to have contracted the coronavirus from an infected but asymptomatic zookeeper .

The zoo has been closed to visitors since March 16. Initially it did not plan to test the other cats showing symptoms, because doing so would require sedation, which can be dangerous.

Both wild and domestic cats had been known to be susceptible to feline coronavirus—but until recently, it was not known whether they could contract SARS-CoV-2.

According to the National Geographic , several domestic animals have tested positive for SARS-CoV-2, the virus that causes COVID-19, including two cats in New York State. A Pomeranian and a German shepherd in Hong Kong, as well as a domestic cat in Belgium, have also tested positive. The U.S. Centers for Disease Control and Prevention has issued new guidelines on the virus for pet owners, saying that while it does not recommend widespread testing at this time, it encourages cat owners to keep their cats indoors whenever possible.

A new Chinese study has found that cats may be able to infect each other. Scientists now are rushing to learn what other species may be able to be infected by it..