The United States is worst-hit by the coronavirus disease (Covid-19) outbreak with over seven million cases. And now, there are reports that the disease has killed thousands of mink.

According to CNN, ranchers in Utah and Wisconsin have lost almost 10,000 mink, the naimals known for their silky fur.

A recent study done by researches at University of California (UCLA), numerous animals may be vulnerable to Sars-CoV-2, the virus that causes Covid-19.

The study, published in Scientific Reports, reports evidence that 26 animals regularly in contact with people may be susceptible to infection. The researchers investigated how the spike protein from Sars-CoV-2 could interact with the ACE2 protein it attaches to when it infects people.

Binding to the protein enables the virus to gain entry into host cells; while it is possible the virus might be able to infect animals via another pathway, it is unlikely based on current evidence that the virus could infect an animal if it cannot form a stable binding complex with ACE2.

“The animals we identified may be at risk of outbreaks that could threaten endangered species or harm the livelihoods of farmers. The animals might also act as reservoirs of the virus, with the potential to re-infect humans later on, as has been documented on mink farms,” said lead author of the study, Professor Christine Orengo.

CNN reported that reports of virus spreading in mink first appeared in August, after some farm workers fell ill. It quoted health experts in Utah as saying that the transmission happened from humans to animals.

Similar cases have been reported from farms in other countries too. Denmark is culling around 1 million mink after finding further coronavirus infections among the animals at farms that breed them for their fur, authorities said.

The Nordic country is the world’s largest producer of mink and had previously culled animals on farms hit by infections, but outbreaks have persisted.

In May, Spain ordered the culling of all 93,000 mink at a farm to prevent human contagion after finding that most of the mink there were infected with the coronavirus.

The Netherlands reported a similar outbreak and undertook a cull after two people were reported to have been infected by mink, though such cases of animal-to-human transmission are believed to be extremely rare.

The UCLA study found that most birds, fish, and reptiles do not appear to be at risk of infection, but the majority of the mammals they reviewed could potentially be infected.