Most horses will have a known history – the owner or handler may have noticed the moment of penetration or found a foreign object embedded when picking out or examining a hoof. The foreign body may be left in place by an owner if there is no risk of the object penetrating deeper if the horse bears weight. In other cases, the penetrating object will have been removed; if this is the case, the person who removed it will ideally have marked the site of penetration on the hoof capsule (a hoof knife leaves a more permanent mark than even a permanent felt pen!) and will have made a note of the depth and direction of penetration.