This thesis is a theoretical examination of animal-assisted interventions, i.e. the targeted use and associated effects of animals on everyday human life. It aims to illustrate the influence that working with animals has on the lives of young and old people, as well as people with mental, physical or chronic illnesses.In order to provide an insight into the diversity of animal-assisted interventions, an overview of the historical development and the definition of the individual areas, which differ in terms of implementation and objectives, is given. Special attention is paid to the discussion of the animals used in animal-assisted work, their training and the presentation of individual areas of application. Various studies are presented to illustrate the areas of activity in a comprehensible manner.