Simple SummaryIn animal-assisted interventions (AAIs) animals are used as adjuncts to therapy to positively affect human health. The practice of implementing dogs into therapeutic environments is emerging and as a result, there has been a growing scientific interest on human health outcomes over the past decades. Research efforts into the canine perspective of AAIs have been scarce. Accordingly, there is little consensus on the impact of such interventions on the animals involved. This paper aimed to contribute to the limited body of knowledge by reviewing available studies on therapy dogs’ welfare during AAIs. Moreover, discussion of theoretical and methodological issues, implications for practice and suggestions for future research are provided.AbstractResearch into the effects of animal-assisted interventions (AAIs) has primarily addressed human health outcomes. In contrast, only few publications deal with the therapy dog experience of AAIs. This paper provides an overview on potential welfare threats that therapy dogs may encounter and presents the results of a review of available studies on welfare indicators for therapy dogs during AAIs. Previous investigations used physiological and behavioral welfare indicators and dog handler surveys to identify work-related stress. Research outcomes are discussed in the light of strengths and weaknesses of the methods used. Study results suggest that frequency and duration of AAI sessions, novelty of the environment, controllability, age and familiarity of recipients modulate animal welfare indicators. However, this review reveals that currently, clear conclusions on how the well-being of dogs is influenced by the performance in AAIs are lacking due to the heterogeneity of programs, recipient and session characteristics, small dog sample sizes and methodological limitations. This paper further aimed to identify unresolved difficulties in previous research to pave the way for future investigations supporting the applicability of scientific findings in practice.