Studies of the effects of Animal-Assisted Interventions (AAIs) face a number of theoretical and practical challenges. Proposed theoretical processes for the effects of AAIs include those that address primarily the animal’s ability to facilitate human–human social engagement, those that emphasize animals’ apparent capacity to trigger social attachments and provide nonhuman social support, those that categorize certain animals as supernormal stimuli, those that advance a biophilia hypothesis that living organisms have an innate ability to attract and hold human attention, and those that promote an integrative biopsychosocial model. Each of these generates potentially testable hypotheses, and the field would benefit from systematic efforts to address their validity. Practical challenges to AAI research include issues of study design and methodology, the heterogeneity of both AAI recipients and the animals participating in these interventions, the welfare of these animals, and the unusual pressure from the public and media to report and publish positive findings. Such challenges need to be carefully considered in designing and implementing future studies in the field.

•Pet ownership is significantly associated with higher levels of social capital.•Social capital was associated with pet ownership in the U.S. and Australia.•Results are not confined to dog owners nor dog walkers.•Pets are an under-recognized conduit for building social capital.

Little is known about ethnic, cultural and socioeconomic differences in childhood ownership and attitudes to pets. The objective of this study was to describe the factors associated with living with different pet types, as well as factors that may influence the intensity of relationship or ‘attachment’ that children have to their pet. Data were collected using a survey of 1021 9–10 year old primary school children in a deprived area of the city of Liverpool, UK.

Owning a pet dog could potentially improve child health through encouraging participation in physical activity, through dog walking. However, evidence to support this is limited and conflicting. In particular, little is known about children’s participation in dog walking and factors that may be associated with this. The objective of this study was to describe the participation of children in dog walking, including their own and those belonging to somebody else, and investigate factors associated with regular walking with their own pet dog.

Despite the lack of a strong evidence base, Animal-Assisted Interventions (AAIs) are becoming increasingly popular as a therapeutic tool for special populations with a variety of psychological and physical conditions. This paper introduces a special series of articles which address the proposed theories and processes underpinning potential effects of AAIs. We recommend strategies for improving the evidence base of AAIs giving specific examples in special populations (e.g., children with Autism Spectrum Disorder [ASD]). We consider the challenges in AAI research and suggest directions for future research.