Cognition is a concept that deals with how individuals perceive and process the environmental information in order to produce appropriate responses. Humans can be considered as a major element in horses’ immediate environment, especially through the direct workrelated relationship these animals share with humans. However, a large part of the working horses might suffer from negative appraisal of the human-horse interactions, as revealed by the high rates of accidents involving horses reported in professionals. Here we will present a set of results highlighting how suffering from poor welfare (inferred from the presence of severe vertebral problems) could affect horses’ relational behaviour and might even “contaminate” the way horses react to humans in subsequent interactions. This, in turn, might also trigger poor welfare states. Indeed, work stressors have been shown to impact on the daily life of horses outside the work sessions, and repeated interspecific conflicts might, as in humans, lead to psychological stress and poor welfare. Keeping that in mind, we will present training/working practices which trigger good human-horse relationship and welfare states, therefore favoring horses’ positive perceptions of the domestic environment.