The equine metabolic sydrome (EMS) is defined as a collection of risk factors for the developmentof endocrinopathic laminitis. In the pathogenesis of this syndrome, the presence of insulin dysregulationis the key determining factor. Important risk factors for the development of insulin dysregulationin horses are the type of feed, the body condition score and genetic factors. Several diagnostic methodshave been described, each of them with their own advantages and disadvantages. Treatment and managementof horses and ponies with EMS rely heavily on the reduction of the risk factors and are mainlybased on dietary interventions.