Psychiatric interactions between humans and animals. The psycho-affective and sensorial interactions between man and animal are at the base of the different types of relations that man keeps with animals. These interactions find interesting extensions in the psychiatric field. An analytic whole about the way man perceives the animal serves as basis for a semiological approach of fantasies. The animal is a transitional object that refers to an inconscious language. Animals' behavioural problems mostly linked with a failing in the relationship between man and animal represent models at various states of human relational, psycho-social and psycho-affective psycho-pathology. In return, the beneficial effect of the relationship with an animal is attested in children ; it is eminently comforting and well-balancing. This relationship is also very positive in adults and in elderly people in order to compensate for a frustration or a psycho-affective deficiency linked with loneliness. All these different aspects of the relationship between man and animal have to be taken into account by the veterinarian.