A four-year-old female tiger named Nadia is believed to be the first known case of an animal infected with Covid-19 in the United States.
The Bronx Zoo in New York City says that test results were confirmed by the National Veterinary Services in Iowa.
Nadia, along with six other big cats are understood to have been infected by an asymptomatic zoo keeper.
The New York based zoo has been closed to the public since March 16.
Reports say that the cats began to show symptoms including a dry cough late last month - after being exposed to the infected zoo keeper, who has not been identified.
Nadia, her sister Azul, as well as two Amur tigers and three African lions who showed symptoms, are all expected to make a full recovery, the zoo said.
There have been a few cases of domestic animals testing positive for Covid-19 elsewhere in the world, but experts have stressed there is no evidence they can become sick or spread the disease.
"This is the first time that any of us know of anywhere in the world that a person infected the animal and the animal got sick," Paul Calle, the chief veterinarian at the zoo, told Reuters news agency on Sunday.
The zoo said that it is not known how the virus will develop in big cats such as tigers and lions because different species can have varying reactions to new infections, but all the animals will be monitored closely.
The big cats did have some decrease in appetite but "are otherwise doing well under veterinary care and are bright, alert, and interacting with their keepers", the zoo said.
Since the announcement of the positive coronavirus cases in the big cats, there has been some public backlash and confusion surrounding the use of testing equipment.
Questions have been raised as to why an animal would be tested over a human - since Covid-19 tests are reported as limited in their availability.
This however highlights some of the confusion surrounding Covid-19 testing.
There are two main differences in the testing process for humans and animals - the test itself and the labs that administer the tests. This means that animal testing for coronavirus should not reduce the availability of COVID-19 tests for people explains Sarah Caddy, a veterinarian at the University of Cambridge and at the Cambridge Institute for Therapeutic Immunology & Infectious Disease (CITIID), where where she studies virus-antibody interactions.
The coronavirus (called Sars-CoV-2, which causes the disease Covid-19) is thought to have originated in wildlife and been passed to humans via a live animal market in Wuhan, China.
The pandemic has been driven by human-to-human transmission, but the infection of Nadia raises new questions about the potential of human-to-animal transmission.
The World Organisation for Animal Health and the World Health Organisation (WHO), say there is currently no evidence to suggest that domesticated animals such as pet dogs or cats can pass on the coronavirus.