Curb is a term used to describe a number of soft-tissue injuries that cause swelling on the distal plantar aspect of the tarsus. Traditionally, the term “curb” is used to describe enlargement of the (long) plantar ligament on the plantar aspect of the calcaneus, but curb-like swelling may also be caused by peritendinous-periligamentous inflammation, superficial or deep digital flexor tendinitis, or a combination of injuries. Curb is primarily an injury of racehorses, particularly Standardbreds, and conformational abnormalities may be predisposing. Lameness varies from absent to severe, depending on the structure involved and the extent of the injury. Diagnosis of the exact nature of the injury is confirmed by ultrasonography. In most cases, treatment involves local anti-inflammatory therapy and NSAIDs in the acute phase and then rest and a controlled exercise program thereafter.