Animal-assisted therapy (AAT) is becoming increasingly popular. The possibilities and guidelines for interventions and methods are very diverse. Currently, published studies mainly concentrate on effects in paediatrics, outpatient therapy and schools. Specific recommendations for AAT in the context of inpatient child and adolescent psychiatry do not exist. This systematic review will attempt to evaluate the existing studies in terms of their methodological quality and specify positive and negative effects, aiming to provide a decision-making aid for everyday clinical practice. A systematic literature search (PubMed/MEDLINE, APA PsycINFO, PubPsych, ProQuest, Google Scholar, and Cochrane Library) according to the PRISMA criteria resulted in 1,908 identified hits, of which 49 articles were reviewed in full text. Three raters contributed to the review of the articles using a criteria-guided codebook. This systematic review is listed in the PROSPERO database (CRD42022358909). Quality analysis was conducted using Effective Public Health Practice Project (EPHPP). Five studies were identified. The majority of these showed deficits in quality. Therapeutic effects and positive influences on the psychopathological status, interpersonal relationships and subjective well-being or attitudes towards canine-assisted therapy (CAT) could be identified. Current studies indicate positive therapeutic effects of CAT in the inpatient treatment of children and adolescents. A cautiously positive perspective is warranted, but a general recommendation for CAT cannot be given. CAT should be carefully considered, planned, and implemented by professionals. For the future, further randomised controlled studies including follow-up studies, larger subject groups and clinically evaluated interventions are necessary to validate the current results.