Canine-assisted activities in schools can benefit students' educational, emotional, and social needs. Furthermore, they could be an effective form of non-clinical mental health treatment for children and adolescents. In the United Kingdom, school dogs are growing in popularity, however, little is known about how parents perceive canine-assisted activities as a treatment option. This is important as parental perceptions can influence engagement, whilst lack of awareness can become a barrier to treatment. This study uses a cross-sectional design to quantitatively explore the acceptability of canine-assisted activities amongst UK-based parents (n = 318) of children aged six to 16 (M = 10.12, SD = 3.22). An online survey used a treatment evaluation to determine acceptability across three use-cases. These included a child reading to dogs to improve literacy skills, a child interacting one-to-one to foster greater self-esteem and social skills, and a classroom dog to improve student behaviour and motivation. Additionally, the scale for generalised anxiety disorder was used to rank child anxiety as high or low, where high was a score equal to or above the UK clinical borderline threshold. The results found canine-assisted activities were less acceptable for the behavioural than the reading and social use-cases. Furthermore, parents of children with high anxiety had higher acceptability scores than parents of children with low anxiety for the reading and social use-cases but not for the behavioural use case. These findings suggest that UK parents' acceptability of canine-assisted activities in schools is mediated by child anxiety score. Furthermore, that parents may be less aware of the benefits of classroom dogs than other types of school-based canine-assisted activities.