Sept. 17 (UPI) -- Six African lions, a Sumatran tiger, and two Amur tigers in the Smithsonian National Zoo tested presumptive positive for COVID-19 this week.
After animal keepers observed symptoms in the big cats -- including decreased appetites, coughing, sneezing, and lethargy -- fecal samples were collected and the tests returned positive.
"Final results are expected in the next few days," the zoo stated in a press release. "All lions and tigers are being treated with anti-inflammatories and anti-nausea medication to address discomfort and decreased appetite."
The zoo said given the distance between the cats and visitors that the public is not at risk of infection.
Staff who have come into contact with the animals have been investigated.
"There is no evidence to pinpoint the source of the infection," the zoo said. "While it is possible the infection was transmitted by an asymptomatic carrier, it has been standard practice for all animal care staff and essential care staff to mask indoors in all public and non-public areas."
The zoo announced that a COVID-19 vaccine designed specifically for animals made by former Pzifer subsidiary Zoetis was authorized by the U.S. Department of Agriculture.
The zoo said that once the vaccine becomes available, a first-round will be administered to select susceptible species.
The Philadelphia Zoo began administering the Zoetis vaccine to animals this week, beginning with a lemur named Charlie. He was among 10 animals who received a shot, including four other ring-tailed lemurs, four western lowland gorillas, and a Sumatran orangutan.