• Historically, the term Curb has been used to describe an enlargement on the plantar aspect of the fibular tarsal bone caused by inflammation and thickening of the long plantar ligament (LPL). However, LPL desmitis is only one of several causes of curb and probably not the most common. 
• Other causes of curb and differentials of LPL desmitis include: 
  • Peritendinous and periligamentous inflammation alone or in combination with one or more injuries of the SDFT, DDFT, or LPL. 
  • Superficial digital flexor tendonitis SDFT: tendinitis. 
  • Deep digital flexor tendonitis Deep digital flexor tendon: tendinitis. 
  • Mixed soft tissue injuries are common and can include any combination of above plus LPL desmitis. 
• Cause: biomechanical stress due to poor conformation Musculoskeletal: conformation, intense exercise, external trauma.
• Signs: enlarged plantar surface of the fibular tarsal bone, acute - heat, pain, chronic cases more diffuse swelling and fibrosis, variable lameness.
• Diagnosis: physical examination Musculoskeletal: physical examination - adult, ultrasonography.
• Treatment: rest and controlled exercise.
• Prognosis: good if no conformational faults.

Presenting signs

• Lameness both acute and chronically progressive.
• Swelling on the plantar distal aspect of the tarsus.

Acute presentation 

• Sudden onset of lameness and swelling. 

Age predisposition 

• Younger racehorses (2-3 years old) are more commonly affected. 

Breed/Species predisposition 

• Racehorses, especially Standardbreds Standardbred (pacers more than trotters) and Western performance horses.
• Not common in pleasure or sport horses. 

Cost considerations 

• Costs of diagnosis and treatment.
• Loss of use during treatment.