Can dogs (Canis familiaris) use a mirror to solve a problem?

The ability of animals to use a mirror, either as a problem-solving tool or for the purposes of self-recognition, has been tested in several species. However, there are no empirical reports of studies using mirrors with companion dogs, which differ from most animals in that they are from infancy often kept in complex environments containing many reflective surfaces, including household mirrors. We used a simple repeated measures design, with no pre-training, to test whether pet dogs (n = 40) understand the concept of reflection. Each dog accompanied their owner into a room containing a large covered mirror. They were given 1 minute to explore the room, following which the mirror was uncovered. After another minute of exploration, the dog was motivated to attend to the mirror by the owner. A second owner then appeared in an adjoining room displaying the dog’s favourite toy. The second owner stood behind the dog but could be seen in the reflective surface of the mirror. Dogs were more likely to attend to the mirror when the second owner was visible than when the owner was not visible in the mirror. Seven dogs turned away from the mirror to look toward the actual location of the owner. Of these, 2 then attended to the owner in the window more than the mirror. It is possible that these 2 dogs understood the real location of the owner and, therefore, the nature of reflection. However, none of these responses was completely unambiguous and most dogs tested showed no evidence of a capacity to spontaneously use the mirror to locate the second owner.