Selection pressures in horse breeding have produced sport horses with increasing physical performance but sometimes declining health and welfare due to conformation and health condition prevalence.
Horse breeding has focused primarily on performance traits that align with human recreational and commercial objectives, with welfare outcomes as secondary considerations. The result in some breeds is a population with elevated rates of developmental orthopaedic disease, respiratory disorders, and other conditions that impair lifetime welfare. Incorporating welfare-relevant health traits — bone density, cardiac health, metabolic efficiency — into breeding evaluation programmes would improve lifetime welfare outcomes without necessarily compromising performance.