What therapeutic potential lies in trained therapy dogs? The book outlines the journey from wolf to therapy dog, focusing on the historically developed relationship between humans and dogs. It describes the training of therapy dogs and their handlers, followed by a discussion of the ethical justification. A selection of existing research findings related to dogs in therapeutic contexts is presented, along with general scientific models explaining the human-animal relationship, mechanisms of action in animal-assisted therapy, and human-dog communication. Conversations with practitioners who professionally use their trained dogs complete the picture. The methodological basis is formed by personal interviews as a means in psychological research, complemented by expert interviews as an additional qualitative research method. The overall result shows that therapy dogs are not a remedy in themselves but act as catalysts in the therapeutic relationship. They can assist clients in personal self-discovery and support their healing processes.