The Covid-19 pandemic has raised awareness about zoonoses, the diseases transmitted by animals to humans. But there are also reverse zoonoses, and they appear to be increasing. They occur when humans transmit pathogens to animals. Their number, as well as that of traditional zoonoses, is expected to grow. Unless we intensify research in the field and adopt a One Health approach, which recognizes the interdependence between the health and well-being of people and animals.