Guide dogs are working dogs that follow the verbal instructions of owners with severe visual impairments, leading them through the environment and toward goals such as a subway entrance ("Find the subway" instruction). During this process, guide dogs incidentally familiarize themselves with their environment. As such, they provide a unique animal model for studying wayfinding abilities in the canine species. In the present descriptive study, 23 skilled guide dogs travelled along a path once and were subsequently tested in a navigation task, with a blindfolded guide dog instructor as the handler. Dogs had difficulty reproducing the path (only 30.43% of the dogs succeeded) and returning (homing) along the previously travelled path (43.47% of the dogs succeeded). However, 80% of them successfully took a shortcut, and 86.95% a detour. This is the first description of the wayfinding abilities of dogs after a single discrete exploration of the path (incidental learning) in systematic experimental conditions. Errors, initiatives and success rates showed that dogs were able to keep track of the goal if the path was short, but errors increased with longer paths, suggesting segmented integration of path characteristics process, as demonstrated in humans. Additionally, errors on homing and detouring, both vital wayfinding tasks, were correlated, suggesting an effect of experience. Initiatives taken by the dogs further suggest flexibility of the spatial representation elaborated. Interestingly, we also found that homing was the only task to benefit from severe visual disability and regular exposure to new journeys, suggesting that these two factors influence the most important wayfinding task. This study therefore highlights qualitative and quantitative wayfinding abilities in the dog species, as well as the factors that account for them, after a single path exploration accompanied by natural ongoing motivation. In the wake of the discovery that dogs are sensitive to the magnetic field, our results provide the basis for developing systematic wayfinding tests for guide dogs.