Simple SummaryRecent years have seen growing research highlighting the benefits of human-animal interaction for the health and wellbeing of autistic children. This is particularly so for interaction with dogs. The human-animal bond advocates that the mutual benefits of this interaction for both humans and animals are crucial and that equal consideration be placed on the welfare of the animals. However, limited research is available exploring the impact on the welfare of dogs when interacting with autistic children. This study aimed to assess changes in stress biomarkers including salivary cortisol, alpha amylase, and oxytocin, as well as behaviour observations of a therapy dog involved in canine-assisted therapy sessions with autistic children. Results from this study found that the therapy dog did not experience significant changes in stress indicators on days working with autistic children, compared to days spent at home. This study highlights the need for further research regarding therapy dog welfare when interacting with autistic children.AbstractHuman-animal bond is defined as the mutually beneficial relationship between humans and animals. Recent years have seen increasing research regarding the benefits of interaction with animals for autistic children. However, there continue to be limited studies exploring the impact of this interaction on the welfare of therapy dogs. As part of a pilot randomised control trial assessing the efficacy of canine-assisted occupational therapy with autistic children, this project assessed welfare markers of the therapy dog involved. A total of twenty-one saliva samples were taken from the therapy dog to assess cortisol, alpha amylase, and oxytocin concentrations at home and throughout the treatment days. Additionally, six hours of therapy session videos were analysed for stress indicators of canine behaviour. No significant differences were found between days spent at home and treatment days for any of the biomarkers or stress indicators. Results suggest that the therapy dog involved did not experience increased stress resulting from interaction with the autistic children throughout the therapy sessions. This study supports the need for further research regarding therapy dog welfare when interacting with autistic children including an increased sample size of therapy dogs and therapists.