Back disorders are amongst the major health-related disorders associated to working conditions in our society. Horses share with humans the exposure to potential physically harmful working conditions leading to back disorders. However, despite their high prevalence, these problems are often unacknowledged in the horse industry, mostly because their diagnosis remains difficult, particularly in field conditions. In the present review, we review the current scientific knowledge on back vertebral, muscular and musculoskeletal disorders. We will first present the existing knowledge about their prevalence and the tools available for diagnosis. Then, the different potential sources of back pain, including anatomical implications, the effect of emotionality and working conditions will be discussed. We finally present the existing behavioral, postural and physiological indicators of back pain that could help an early detection of back disorders.