Two American cats were infected with COVID-19 after their owners were sickened by the virus and fully recovered after between eight and 10 days of symptoms, in the first known U.S.-based pets affected by the deadly global pandemic, according to a study by the Centers for Disease Control and Prevention.

The new Morbidity and Mortality Weekly Report released on Monday tracked how the virus spread between the cats and their owners, finding that “human-to-animal transmission of SARS-CoV-2 can occasionally occur” and confirming that “animals are not known to play a substantial role in spreading COVID-19.”

A small number of other species worldwide have been infected, including tigers, lions, dogs, mink, ferrets, golden Syrian hamsters, and Egyptian fruit bats. The report concluded that “persons with COVID-19 should avoid contact with animals” and that any pets “that test positive for SARS-CoV-2 should be monitored and separated from persons and other animals until they recover.”