COVID-19 Is Devastating Captive Snow Leopards

Felines are highly susceptible to COVID-19 because – like humans – the cells of their respiratory tracts express a lot of the enzyme ACE2 on their membranes, and their ACE2 enzyme is very similar to ours. SARS-CoV-2, the virus that causes COVID-19, binds to ACE2 to gain access to cells. The more ACE2 that cells have, the more they are vulnerable to infection. Various studies conducted across the globe have probed house cats for antibodies against SARS-CoV-2, a sign of prior infection. Anywhere from five percent to a quarter have likely contracted the virus at some point, almost certainly from their human companions.

Luckily for cats, they don't express nearly as much ACE2 in their lung cells as humans do, which reduces their risk of severe disease. Most cats don't even show symptoms to a COVID-19 infection. Why, then, does this trend not seem to hold for snow leopards? Scientists aren't sure, but there are a couple possibilities. First, the five snow leopard deaths may just be unlucky, a statistical artifact. Alternatively, leopards' lung cells may express more ACE2 than their cat cousins. Lab studies are needed to shed light on this speculation.

https://www.realclearscience.com/blog/2022/02/19/covid-19_is_devastating_captive_snow_leopards_816689.html