They said the lions and tigers are being closely monitored.
The big cats are displaying symptoms of the virus, including nasal discharge and coughing. They live in groups with their specific species and are not being separated at this time, officials said.
A zoo spokeswoman said the coronavirus was probably transmitted to the big cats from a human who may have been asymptomatic.
Zookeepers first noticed last weekend that the big cats were coughing and sneezing. They also acted lethargic and had decreased appetites. Fecal samples were taken and tested.
Officials said the cats are being treated with antibiotics.
In a statement, officials at the zoo said that “because their condition does not require they remain inside, staff will manage the cats’ access to their outdoor habitats.” And “given the substantial distance between the animals and visitors, the public is not at risk.”
Zoo officials said no other animals are “showing any signs of infection.”
The zoo said it has protocols in place requiring the use of personal protective equipment and other hygiene and cleaning for all staff to follow. All of its staff and animal caretakers are required to wear masks indoors and in all public and nonpublic areas, officials said.
Zoo officials said they’ve done “a thorough investigation of all staff that were in close proximity to the lions and tigers. There is no evidence to pinpoint the source of the infection," according to a statement. They also said, “health and vaccination status of employees is confidential medical information.”
Officials said they have plans to vaccinate some of their animals in the coming months using a product made by Zoetis, a company that spun off from Pfizer. Zoetis has given more than 11,000 doses of its coronavirus vaccine for animals to zoos and animal sanctuaries around the country. The company’s vaccine is authorized for use on a case-by-case basis by the U.S. Department of Agriculture and state veterinarians, said a company spokeswoman.
Earlier this week, the Maryland Zoo in Baltimore said it planned to vaccinate a number of its animals, including lions, chimps and otters, with the Zoetis product.
No animals at the Maryland Zoo have gotten covid-19, the disease caused by the virus, since the pandemic started more than a year ago. But the vaccine will “add another layer of protection for the animals in our care,” Ellen Bronson, senior director of animal health, conservation and research at the Maryland Zoo, said in a statement.
According to the Centers for Disease Control and Prevention, the coronavirus can infect mammals. There have been cases of animals at zoos getting sick, and many experts said they typically got the virus after being in close contact with humans who had it.
Experts have been most worried about orangutans, gorillas and chimpanzees catching the coronavirus because they are susceptible to many illnesses that affect humans, and a simple cold can be deadly for them.
Recently, officials at the Zoo Atlanta said some of their gorillas tested positive for the coronavirus, and they have plans to vaccinate them once they’re better.