Horse Side Vet Guide ®

Equine Health Resource

Annular Ligament Disease, Palmar or Plantar

A transverse sheet of tissue called the annular ligament lies over the flexor tendons at the level of the fetlock joint on both front and hind limbs. When this ligament is inflamed or injured, it can contribute to pain and lameness by constricting the flexor tendons and flexor tendon sheath in the fetlock. Lameness associated with this constriction can be mild to moderate and usually worsens with exercise.

A key characteristic of this problem is a bubble of swelling that abruptly cinches in at the annular ligament. However, often the annular ligament is only part of the problem. The flexor tendons within the tendon sheath may be injured as well. Radiographs and ultrasound should be performed to refine the diagnosis.


  • Is there another underlying problem?
  • Is the annular ligament constriction primary or secondary?
  • Is the annular ligament thickened on ultrasound?
  • How much do you think that annular ligament resection will help the lameness?

    Maintain good hoof care. Ensure horse's fitness is compatible with performance expectation.
    Author: Doug Thal DVM Dipl. ABVP


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