The Georgia Aquarium in Atlanta says some of its otters tested positive for the coronavirus after they showed mild respiratory symptoms.

The aquarium said in a news release Sunday that the Asian small-clawed otters were tested after they had common COVID-19 symptoms, like sneezing, runny noses, mild lethargy and coughing. They are off exhibit and being cared for behind the scenes, where they were already improving and are expected to make a full recovery.

The aquarium has been following recommended health and safety protocols, but it is suspected the otters may have caught the infection from an asymptomatic staffer.