Affected structures

Apart from the hoof capsule and the dermis, an injury from a picked-up nail can affect the following structures alone or in combination:

• Pedal bone

• Deep flexor tendon (DFT)

• Distal sesamoidean (impar) ligament connecting the navicular and pedal bones, possibly also with involvement of the coffin joint 

• Navicular bursa, possibly also with involvement of the navicular bone• Digital flexor tendon sheath (DFTS)

• Digital cushion

• Lateral cartilage of the hoof (not shown)

Once the foreign body is removed, the entry hole generally closes up quickly and becomes virtually airtight, due to the elasticity of the horn. Since neither blood nor discharge can drain from the tightly closed wound, the risk of wound infection caused by a foreign body is particularly high. The lack of oxygen means that infections caused by anaerobic microbes, e.g. tetanus bacteria (Clostridium tetani), are the most feared complications.