Brain-Computer Interfaces (BCIs) have shown remarkable potential in human neuroscience and medicine. Yet, their application with animals, in particular canines, remains largely unexplored. This paper delves into the background, systems overview, implementation details, potential features, prospective use-cases and challenges, of canine BCIs. While the focus is on EEG-based BCIs, other modalities such as fNIRS are also discussed. Despite significant challenges, such as hardware design and data inference, I argue that canine BCIs hold potential to significantly push forward our understanding of canine cognition, and facilitate a higher bandwidth of human- canine communication, collaboration, and flourishing.