Veterinary advice should be sought before applying any treatment or vaccine.


Sidebone is a term used to describe ossification in one or both of the lateral cartilages (also referred to as collateral or ungular cartilages) located on each side of the pedal bone in the horse's foot.
Sidebone Comparison
The condition occurs most commonly in Heavy draft, Cob, and Icelandic breeds, and horses with poorly balanced feet or uneven loading of the heels. Sidebone usually occurs in the forelimb, cases involving the hindlimb are usually associated with acute trauma or chronic repetitive trauma (such as punctures, chronic bruising from interference, or lacerations), resulting in chronic inflammatory changes and osseous metaplasia of the cartilage.

The lateral cartilages provide support and protection for the soft tissues at the back of the foot. Ossification typically starts from distal to proximal, and may initially induce lameness in affected horses. The only way to verify the extent of ossification that has occurred is through radiographic images. Nuclear scintigraphic examination may also be helpful to help differentiate between a fractured sidebone and a separate center of ossification.


Prominent, hard, rigid and bony enlargement proximal to the coronary band
Short and choppy stride
Uneven shoe wear


  • History
  • Clinical signs
  • Physical exam
  • Radiographs
  • Nuclear scintigraphic exam


Regular hoof trimmingFeet should be kept properly balanced to distribute the weight-bearing evenly, conducted by an experienced farrier at regular intervals less than 6 weeks in duration.
Bar shoesMay be useful in the presence of lateromedial foot imbalance.


  • Ensure horse gets shod in regular intervals.
  • Avoid lots of work on hard ground such as roads.

Scientific Research References

Good Overviews

  • sidebone icon
  • sidebone icon

Risk Factors

  • Heavy draft breeds, Cob, or Icelandic horses
  • Horses with poorly balanced feet
  • Horses with narrow, upright feet, especially those with a toe in or toe out hoof conformation.
  • Frequent exercise on hard surfaces
  • Previous over reaching injury or trauma to the cartilages from wire cuts or other injury that causes direct damage to the cartilages.
  • Concurrent collateral ligament desmitis of the DIP joint
  • Horses with a low height to bodyweight ratio