Three females, called Zala, Nima and Run Run, and a male named Kiumbe, were given Covid tests after a zookeeper noticed they were displaying symptoms which were similar to the signs of coronavirus.
Despite the ferocious reputation of lions, they were familiar enough with the staff looking after them that the four creatures were content to allow zookeepers to swab their noses and mouths in the same way that humans are tested.
Although it is not yet known how the lions contracted Covid, two human staff at the zoo have so far also tested positive.
Barcelona Zoo said it had contacted their counterparts at the Bronx Zoo in New York, where the first confirmed cases of Covid in large cats has been reported.
In April, four tigers and three lions were all confirmed to have caught coronavirus. Other than a dry cough, none of the animals showed any other symptoms and all recovered.
“The Zoo has 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,” Barcelona Zoo said in a statement.
The US Centers for Disease Control and Prevention have collated multiple cases of large felines catching the virus in zoos, including a puma in South Africa and tigers in a Tennessee zoo.
So far, the zookeepers in Spain were only giving the four lions generic veterinary care to alleviate their symptoms, comparable to if the beasts had caught a more normal cold or flu.
“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,” the statement added.
Kiumbe, the male, is four years old, while the three females are all 16, which while old for wild animals is only approximately middle age for those living in captivity, where they commonly live for up to 30 years.
All four have had no contact with other animals and there is no sign Covid is spreading any further. The zoo remains open to visitors, as a November lockdown is gradually relaxed by the Catalan authorities following a second wave of the virus in the autumn.
Earlier in the pandemic, American public health authorities recommended anyone experiencing Covid symptoms should self-isolate from their pets as well as other people “out of an abundance of caution”.
It is believed that the novel virus first infected humans after evolving within an animal, probably a bat.
Although it is not fully known which animals can and cannot contract the virus from contact with infected humans, there have been cases in domestic dogs and cats as well as large outbreaks among mink around the world.
There is some limited early research which shows that while dogs can catch Covid they seem to be less likely to pass it on.
Experiments have also revealed creatures including ferrets, tree shrews and marmosets can also become infected and display symptoms.
So far, there is no compelling evidence these animals can spread their infections back to humans.
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