Six lions and three tigers at the Smithsonian’s National Zoo in Washington, D.C., are believed to have been infected with COVID-19 after returning “presumptive positive” tests this week.
The zoo said in a Friday press release that a group of African lions, along with a Sumatran tiger and two Amur tigers, were positive for COVID-19 in initial tests based on fecal samples, with final results expected in the next few days.
The zoo said that it conducted the tests after animal keepers last weekend “observed decreased appetites, coughing, sneezing and lethargy in several lions and tigers.”
The statement added that all of the infected animals “are being treated with antibiotics for presumptive secondary bacterial pneumonia.”
“They remain under close observation and, because their condition does not require they remain inside, staff will manage the cats’ access to their outdoor habitats,” the zoo said, adding that the public is not at risk due to “substantial distance between the animals and visitors.”
No additional animals at the zoo, which is one of the oldest in the U.S., appear to have been infected, zoo officials said.
“The Zoo has conducted a thorough investigation of all staff that were in close proximity to the lions and tigers,” the statement continued, with officials noting that there had been “no evidence to pinpoint the source of the infection.”
“While it is possible the infection was transmitted by an asymptomatic carrier, it has been standard practice for all animal care staff and essential staff to mask indoors in all public and non-public areas,” the zoo added.
Animals at the National Zoo are also expected to soon begin receiving the COVID-19 vaccine made specifically for animals by Zoetis that has been authorized by the Department of Agriculture.
The news of the infections comes a week after Zoo Atlanta announced that 13 of its gorillas had tested positive for COVID-19 after staff members began noticing similar symptoms of coughing and change in appetite.
The Zoo Atlanta said that once the gorillas recovered, they would be getting the Zoetis vaccine, with all 20 gorillas at the zoo to continue undergoing regular COVID-19 testing.
While the Centers for Disease Control and Prevention has said that evidence suggests the risk of animals spreading the virus that causes COVID-19 to humans is extremely low, people may be able to transmit the virus to animals in some cases, including during close contacts.