Terra Natura Tiger
The big cat from the Terra Natura park in a coastal resort town in Spain attacked and killed its 37-year-old female zookeeper on Saturday. Facebook/Terra Natura Zoo

A 4-year-old female Malayan tiger at the Bronx Zoo in New York City tested positive for the coronavirus. This is the first instance of a tiger being infected with COVID-19.

In a statement, the United States Department of Agriculture's (USDA) Veterinary Services Laboratories confirmed that the tiger, Nadia, tested positive for the virus that causes COVID-19, explaining that she and several other tigers and lions were tested for the virus after they began presenting symptoms of a respiratory illness.

According to the Wildlife Conservation Society (WCS), apart from Nadia and her sister Azul, two Amur tigers and three African lions also developed dry cough and a marked decrease in appetite. Fortunately, the other big cats in the same exhibit as well as the other animals in the zoo are not showing any clinical signs.

"We tested the cat out of an abundance of caution and will ensure any knowledge we gain about COVID-19 will contribute to the world's continuing understanding of this novel coronavirus," WCS said in a statement. "It is not known how this disease will develop in big cats since different species can react differently to novel infections, but we will continue to monitor them closely and anticipate full recoveries."

Since the zoo has been closed since the middle of March and the large cats fell ill on March 27, officials believe that they contracted the coronavirus after being exposed to an asymptomatic zoo employee who was "actively shedding the virus."

According to the USDA, this is the first case of a tiger being infected with COVID-19. This leads to the question of whether animals can pass COVID-19 to people but, according to the agency, there is so far no evidence that animals, including livestock and pets, can transmit COVID-19 back to humans.

In a small number of earlier cases outside of the U.S. where pets such as dogs and cats contracted the virus after being in close contact with contagious people, authorities concluded that pets cannot pass the virus to humans but, they can test positive after being exposed to infected humans.

"It's important to assure pet owners and animal owners that at this time there isn't any evidence that they can spread the virus," USDA official and veterinarian Dr. Jane Rooney, said.

As such, people who are infected with COVID-19 or are presenting its symptoms should avoid being in close contact with their pets to avoid infecting them. This includes avoiding interactions such as petting, snuggling, sharing food and being kissed or licked. If contact cannot be avoided, particularly when the person has to take care of the pet, it is important to thoroughly wash their hands before and after the interaction.

So far, there are no reports of any pets or livestock that are positive with the virus in the U.S.