The topic of this thesis is the relationship between animals and humans throughout history; specifically the role of the dog in the service of man, which changed over time. Humans and animals are inseparably connected, whether in some kind of harmony, mutually beneficial relationship or conflict. The dog as man's best friend, pet, and help in medicine and various public services is in a way a novelty of our time, given that in history it primarily served as a guard for houses or other animals and as a help in hunting. The paper tries to credibly show the changes that the dog went through in its relationship with man and how it reached today's status as one of the most desirable animal "helpers" in various fields of activity in the service of man. The work consists of two parts, where the first deals with the theoretical part of the study of the relationship between animals and humans, the development and anatomy of dogs throughout history, and deals with the relationship between dogs and humans throughout history until today. The second part tries to investigate the role of the dog in the service of man today, and through interviews with people who are users of working dogs or work closely in their job with them. The goal is to find out how and why the role of the dog in man's service has changed and what are the main advantages of such a relationship today, in what ways dogs can influence the health of the individual, but also the well-being of the entire society.