The effect of dog ownership on the physical activity and social network of the owners is getting more attention nowadays. Dogs may be able to positively influence risk factors for preventing non-communicable diseases. The basis for this qualitative study is mainly established on a literature study and the data gathered is derived from two focus group interviews followed by six detailed individual interviews. From the gathered data it can be concluded that the influence of dogs on the physical activity and social network needs to be viewed from a comprehensive framework based on three environments: the social, physical and policy environment. Besides the main environmental structures, a more in depth structure can be seen to influence the intention to walk and social network. The characteristics of the dog, the characteristics of the owner, the personal beliefs and the bond between owner and dog, are mentioned to influence the key perceptions. These key perceptions are the motivation and obligation to walk with the dog, the social support provided by the dog and the perceived barriers and benefits. Dogs are said to be able to positively influence these perceptions of the owner, which enables dogs to maintain the owners’ walking behavior. The point that dogs can positively influence some key factors of current mental and physical health problems, raises the possibility to develop a dog intervention. Both owners and non-owners may benefit from dog interventions. However before starting with the development of an intervention, it is important to examine the needs of the population. A needs assessment study would be a good first step in the development process of a dog intervention and if the results are positive, a concrete plan for a dog intervention can be made