Since the beginning of domestication, the living conditions which are shared between humans and companion animals have changed dramatically. More time is spent together indoors, not only in urban places, but also in rural areas. Among the positive aspects is the asthma- and allergy-protective effect of living with pets during fetal development and infancy. In addition, there are benefits in terms of social interactions and mental health for humans and, as far as can be assessed, also for companion animals. Animals, especially dogs, are also brought more often to workplaces and schools. Thus, a number of the positive effects on social and health aspects are likely to come to these places of activity as well. Optimal preparation of the workplace for the animal by the owner, as well as instruction of employees and, additionally, training of the animal could help reduce potentially adverse effects. Such negative effects could include interference with work processes (phone calls, meetings, lectures, sales calls), and fear of bites or accident hazards by colleagues. In the sense of a One Health approach, this article focuses on the importance of animals (especially dogs) and humans sharing the home, but also the workplace. The effects on allergic/asthmatic diseases as well as on social and mental factors are particularly highlighted, as the latter may also contribute to these diseases. Only a few studies have examined the effects of contact between adult people, who are not pet owners themselves, with dogs in the work environment; so there is clearly a need for further research.