Sudden, unexpected death in horses, due to vascular rupture, is a relatively frequent but poorly understood event that not only affects riders’safety, but also the public opinion on the horse industry in general. Rupture of a specific blood vessel may happen at rest, during foaling, breeding or intensive exercise. The reason why certain blood vessels suddenly rupture is unknown but a relation with age, gender, breed and intensive training has been suggested. In human medicine the stiffness of the arterial wall, the arterial wall stiffness (AWS), is known to be an independent predictor for cardiovascular disease and different techniques are available to evaluate this AWS. The aim of this project is to develop a new, easy to use, non-invasive method for measurement and evaluation of arterial wall stiffness in horses. Subsequently this technique will be used to identify the effect of age, gender, breed and intensive training on the arterial wall stiffness in horses. The final goal is to be able to perform risk assessment of vascular death in horses and thus reduce risks for sudden death in horses.