A further four tigers and three lions at the Bronx Zoo in New York City have tested positive for coronavirus, the Wildlife Conservation Society confirmed.

The news comes after the zoo’s four-year-old female tiger Nadia tested positive for the virus earlier this month, having developed a dry cough.

The Wildlife Conservation Society said in a statement: “We tested the tigers and lions 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.

“The testing of these cats was done in veterinary laboratories and resources used did not take from those being used for human testing.”

The Wildlife Conservation Society said all eight cats ‘continue to do well’ and are ‘behaving normally, eating well, and their coughing is greatly reduced’.

In a statement released after confirmation that Nadia had been infected, the Wildlife Conservation Society said the infected animals had come into contact with a worker who tested positive for Covid-19.

“Our cats were infected by a person caring for them who was asymptomatically infected with the virus or before that person developed symptoms,” the statement said.

“Appropriate preventive measures are now in place for all staff who are caring for them, and the other cats in our four WCS zoos, to prevent further exposure of any other of our zoo cats.

“We are grateful for the cooperation and support of the New York State Diagnostic Laboratory at Cornell University and the University of Illinois College of Veterinary Medicine Veterinary Diagnostic Laboratory, where the initial Covid-19 testing of samples from the tiger were performed; the USDA National Veterinary Services Laboratory where confirmatory testing was conducted; USDA Animal and Plant Health Inspection Service; and the New York and Illinois State Veterinarians and the New York City Department of Health and Mental Hygiene for their assistance.”

Researchers are still trying to understand how the novel coronavirus might affect animals, with the Centers for Disease Control and Prevention confirming earlier this week that two cats in New York City have tested positive for the virus.

A spokesman said: “There is no evidence that pets play a role in spreading the virus in the United States.

“Therefore, there is no justification in taking measures against companion animals that may compromise their welfare.

“Further studies are needed to understand if and how different animals, including pets, could be affected.”