Geographical scholarship is increasingly concerned with how knowledges count in human-nonhuman relations, including questions of what it takes to achieve responsible practice, and the forms of expertise that shape corporeal encounters. This paper highlights how the outdoors comes to be known matters for the integrity of human and non-human bodies performing and encountered in outdoor spaces. It examines some of the ways of knowing demanded in accomplishing responsible outdoor access with dogs, in terms of constituting response-ability -or the capacity to respond -across species and geographical difference. Through mobile and visual ethnographic methods enabling episodes and repertoires of canine-human enactments to be witnessed and recounted, we identify ways of knowing the outdoors that exceed cognition of the formal scriptings of conduct, yet are crucial to preventing its transgression through engendering capacities to respond. We identify in particular the role of anticipatory knowledges, and argue that better account needs to be taken of the embodied preparatory and pre-emptory ways of knowing that make the mutual doings of response-ability across spatial and species difference possible. These encompass a set of temporally interleaving spatio-corporeal competencies that render the crux time-spaces of 'irresponsible' human-nonhuman ruptures preventable rather than merely recognisable. They work by shaping and being attuned to how dog and human bodies become articulate to each other in relation to the shifting ecologies, topographies, terrains and proximities of an outdoor excursion. Consequently, we raise the question of the work of responsibility done (or not) in terms of our human obligations to animals when attentions become focused on codified rather than the broader range of outdoor knowledges.