Ringbone is a degenerative condition that affects the bones and joints in the horse’s lower limbs. It is characterized by the inflammation of surrounding connective tissue, triggering the formation of bony growths around the affected joints. [1][2]

These visible bony growths can manifest on the front of the pastern and coffin bones, potentially resulting in permanent fusion of bones in the joint. [3][4] Ringbone may or may not cause pain, but common signs include lameness, stiffness, and swelling of the pastern joints. [4]

The development of ringbone may be influenced by various factors, including conformation, trauma, repetitive stress and joint instability. [4] It can occur in horses of any age or breed but is more commonly seen in older horses.

To ensure the horse’s comfort and soundness, regular monitoring and effective management of ringbone are essential. Seek guidance from a veterinarian and a knowledgeable farrier to develop a comprehensive, individualized treatment plan.

Ringbone in Horses

Ringbone is a form of osteoarthritis that can occur in both the front and hind limbs of horses. Osteoarthritis is a specific type of arthritis (degenerative joint disease) that involves the degeneration of joint cartilage and the underlying bone.

Ringbone in horses primarily affects the pastern and/or coffin joints. These are the joints located between the long pastern bone (P1 or proximal phalanx) and the short pastern bone (P2 or middle phalanx), and between the short pastern bone (P2) and the coffin bone (P3) respectively.

The pastern, located between the hoof and fetlock joint, is a flexible and resilient structure that plays a vital role in absorbing shock and providing support during movement. It serves to cushion the impact of the horse’s weight and forces generated during locomotion. [1]

Ringbone is characterized by the development of bony growths, called exostoses, along the edges of the affected joints within the pastern. These bony growths are the result of the body’s attempt to repair and stabilize the damaged joint.

As the condition progresses, these bony growths can cause pain, lameness, stiffness, inflammation, and reduced range of motion in the affected limb.

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Low vs. High Ringbone

Ringbone is classified into two types based on the location of the bony growths:

  • High ringbone: Also known as proximal interphalangeal (PIP) joint arthritis, affects the joint between the long pastern bone (P1) and the short pastern bone (P2). This condition is a common cause of lameness in horses of all breeds. [5][6]
  • Low ringbone: Also known as distal interphalangeal (DIP) joint arthritis, affects the joint between the short pastern bone (P2 or middle phalanx) and the coffin bone (P3 or distal phalanx). The DIP joint is situated inside the hoof, below the coronary band. [7]

The specific regions of the horse’s leg where degenerative changes take place can influence the severity of lameness and the response to treatment.

Articular vs. Non-Articular Ringbone

Ringbone can also be classified into types based on the location of the bony growths within the joint. This classification takes into account whether the bony growths occur on the joint surfaces or on the structures surrounding the joint.

  • Articular ringbone: Characterized by the development of bony growths on the joint surface, specifically in the proximal interphalangeal (PIP) or distal interphalangeal (DIP) joint. It is associated with more severe lameness and joint pain compared to non-articular ringbone, as the bony growth directly affects the joint surfaces. [3][8]
  • Articular ringbone occurs when the periosteum, the outer sheath of the bone, becomes inflamed due to stress-induced pulling and tearing of the surrounding ligaments an