COVID-19 isn’t merely a human disease—animals can catch it too. Species infected so far include domestic cats, lions, tigers, mink, and dogs. In January, three gorillas at the San Diego Zoo Safari Park tested positive, the first such cases in any non-human primate.

The gorillas—which were likely infected by an asymptomatic keeper—recovered, in part with medical help. Winston, the troop’s 49-year-old leader, who has an underlying heart condition, developed pneumonia and was given antibiotics, heart medication, and monoclonal antibody therapy.  

That great apes are susceptible to the coronavirus doesn’t surprise researchers, given the similarity between humans and primates, including gorillas, chimpanzees, and orangutans. The worry now is that these animals could be exposed to COVID-19 in the wild.

A new