Focusing on human–dog relations, this article develops a more-than-human approach to the sensing of urban insecurity. Extending work on the embodied, sensory dimension of fear and other security affects, it centers the role of non-human, canine bodies in processes of risk assessment. Drawing on research in Kingston, Jamaica, I explore how a range of city dwellers learn to sense danger with and through security dogs. How do those who live and work in the city construct and experience its threats through attunement to their dogs’ olfactory, auditory, and visual acuity? And how does this interspecies sensing of urban danger co-produce distributions of urban safety and precarity? In this context, I suggest, dogs are not only a companion species but also a “prosthetic species,” animals that enhance and extend the limits of the human senses, enabling a more-than-human knowledge of what threats look, sound, and smell like. I discuss such practices of interspecies sensing and their effects, concentrating on the identification of criminal, political, and spiritual forms of danger. Together, such instances of interspecies sensing can provide new insights into the everyday perception, construction, and negotiation of fearful cityscapes.