Previous research suggests that dogs (Canis familiaris) form attachment bonds to their owners and that the strengths of the attachment can vary. However, it does not seem reasonable to believe that all dogs share the same attachment style, considering their differences in genetic background, their previous experiences and the many different caregiving strategies that are known to exist among humans. Rather, the level of security felt by dogs towards their owner probably varies, as seen in children towards their parent. The aim of this review is to highlight the strengths and weaknesses of current approaches of investigating the dog-human relationship in order to contribute to this rapidly developing field. The main focus is related to trying to increase our understanding about the dog’s experience of the relationship. Current knowledge about the dog-human relationship is reviewed and discussed. Concepts from human psychology are used to clarify some of the terms that are also used in anthrozoology, thereby giving stronger theoretical support to our suggestions of how to adapt and apply methods to further develop assessments of dog-owner relationships. We highlight potential factors that deserve more attention in future studies to improve our understanding of the dog-human relationship, and we suggest a more coordinated approach, with a unified terminology, to develop an overarching framework. Suggestions for the future to achieve this include focusing on attachment styles at the individual dog level, rather than talking about the ‘average’ dog. Furthermore, a dyadic approach is suggested, where both the attributes of the dog (its attachment style) and the owner (its caregiving strategy) are incorporated when assessing the relationship. One way to do this is to focus on the balance between the dog’s separation distress and how effective the owner’s caregiving strategy is in calming the dog when reunited. The consequence, from an applied point of view, is owners becoming more aware of what type of attachment style their dog has and what caregiving strategy they have. Knowing this may contribute to identifying sources of conflict in past or present relationships, so helping owners form more successful and positive relationships in the future. It may also contribute to better matching when rehoming shelter dogs.