This article analyses studies and controversies regarding the role of canids - domestic dogs and wild foxes - in the transmission and control of American visceral leishmaniasis, from a Brazilian perspective, since the identification of the first cases in the early 20th century. The political and institutional factors that shaped these studies and controversies are examined, as well as the measures adopted against hosts and vectors across successive periods characterized by different health policies and health system configurations. The article highlights two forms of resistance to the mass culling of domestic dogs, a cornerstone of public health campaigns against voisceral leishmaniasis in Brazil: the opposition stemming from the human populations mnost affected by it, followed by the growing opposition from scientists and public health experts to this course of action, driven by the fact that it failed to prevent the disease's geographical expansion and urbanization in the country. The article concludes by examining an innovation that helped break the deadlock in visceral leishmaniasis control: the use of insecticide-impregnated collars on dogs, adapting a technique previously applied solely to vector control to animal health. Finally, these sociotechnical processes are contextualized within the broaderpolitical and cultural framework of an emerging global health paradigm: One Health. Portuguese version: https://doi.org/10.1590/SciELOPreprints.18317