In the framework of the early prevention of problems in the owner-dog relationship, it is important to have a broad perspective on the development of this relationship over time, starting before people actually acquire a dog. People who currently (or previously) own(ed) a dog can rely on their experiences when considering a new dog, while this knowledge is unavailable to first time dog-owners. In this study, we explore how self-efficacy, social comparison, perceptions about the (dis)advantages of ownership and commitment to the dog (so-called social cognitive factors), problematic canine behaviors, perceived costs, and satisfaction with the dog change over time. We examine changes from the motivational phase of relationship development (before acquisition of the dog) into the experience phase (six and twelve months after acquisition of the dog). We explore if patterns are different in experienced (previous (n = 73) and current (n = 80)) versus unexperienced (first time (n = 30) dog owners. The respondents filled in three online questionnaires-once before and twice after acquisition of their dog. From T0 (before acquisition of the dog) to T1 (having the dog for six months) participants (especially those with no ownership experience) had to adjust their perceptions about dogs and dog ownership. Experiencing the relationship for an additional year (from T1 to T2) barely changed the social cognitive factors, satisfaction, and perceived costs. A small decline in problematic canine behaviors was present among the experienced dog owners between T1 and T2. To conclude, perceptions about dogs and dog ownership change over time, but after testing these perceptions with reality, they become stable after about six months.