The term “picked-up nail” refers to penetration of the hoof by a sharp foreign body such as a nail, a screw, a piece of broken glass, a bit of wire or even a horseshoe clip. In theory, the foreign body can penetrate the hoof capsule anywhere; however, due to its anatomical structure, it is the ridges of the frog and its collateral sulci that are most commonly affected.

As it penetrates the hoof, the foreign object carries micro-organisms into the wound. This contamination of structures inside the hoof can quickly result in a dangerous infection affecting soft-tissue structures within the hoof; this type of injury therefore needs to be taken extremely seriously. If the penetration is to a depth of more than 1cm, or if the depth cannot be evaluated by the owner (or farrier), a vet should be consulted. Particularly deep penetration in certain critical locations may even result in a horse’s referral to a specialist clinic.