Four lions at Spain’s Barcelona Zoo have tested positive for the coronavirus, Reuters reported on Tuesday. Two staff members working at the zoo have also contracted the infection after the outbreak came to light last month.

Three female lions – Zala, Nima and Run Run – and a male named Kiumbe were tested after they began showing symptoms of Covid-19. All four are 16 years old and have had no contact with other animals at the zoo. Keepers carried out polymerase chain reaction, or PCR tests, similar to the way humans are tested for the infection.

This is only the second known case of large felines contracting the infection. In April, three lions and four tigers had tested positive for Covid-19 at the Bronx Zoo in New York City. All the animals have now recovered.

“We have contacted and collaborated with international experts such as the Veterinary Service of the Bronx Zoo, the only one that has documented cases of Sars-CoV-2 infection in felines,” the Barcelona zoo said in a statement. “The lions were given veterinary care for their mild clinical condition –similar to a very mild flu condition – through anti-inflammatory treatment and close monitoring, and the animals responded well.”