Dear Readers: Several mammalian species, including cats, are susceptible to infection by people with COVID-19. A feline lockdown is called for, keeping all cats indoors (except for safe enclosures, aka “catios”). Otherwise, cats coming from homes with infected people could spread the virus to other cats. Back at home, those other cats could then infect any pet ferrets, rabbits or hamsters present. Infected cats could also spread the disease to wildlife, notably foxes, squirrels and rabbits.

Free-roaming and “working” rat-control cats could create a coronavirus pool of infection in various communities, becoming a link between an infected human population and wildlife already at risk (doi.org/10.1111/mam.12225). If the virus infecting cats (including the big cats in zoos) ever mutates and becomes transmissible back to humans, there could be a public backlash of cat and/or wildlife extermination, as occurred centuries ago during the Black Death.

At least one company, Applied DNA Sciences, plans to initiate clinical trials of one of its vaccine candidates for veterinary use to prevent coronavirus infections in domestic cats. The trials will be conducted in collaboration with biotechnology firm EvviVax S.R.L. upon receiving approval from the U.S. Department of Agriculture.

Precautionary measures — like wearing masks, washing