Horse Side Vet Guide ®

Equine Health Resource

Flexural Deformity Fetlock Joint, SDFT

Synonyms: Contracted Tendon, Contracted Foal, Contracted Fetlock, Superficial Digital Flexor Tendon (SDFT) Injury

If the tendons that support the back of the fetlock joint are too “short” or tight (relative to the length of the cannon bone), the result is a very upright fetlock joint.

The structures involved in this syndrome are the superficial digital flexor tendon, the deep digital flexor tendon, the suspensory ligament and the joint capsule itself.

The effective length of the deep digital and superficial flexor tendons can be changed with check ligament surgeries (inferior check, and sometimes superior check). In very severe conditions, even the superficial digital flexor tendon can be cut. Like problems involving the deep digital flexor tendon, foals can be born with this disorder, or can acquire it during growth. Each of these syndromes is likely to have a different cause and is managed differently.

In cases of acquired flexural deformity, over-nutrition, imbalanced nutrition and underlying lameness can be to blame. The problem can be present on either front or hind limbs.


  • Why does the foal have this disorder?
  • What treatments are available and how successful are they?
  • Would I expect to see this disorder in progeny of this horse?
  • How should nutrition be modified to manage this problem?
  • What exercise protocol is best to manage this problem?

    Select for horses of good conformation. Ensure that nutrition is balanced. Do not overfeed energy to growing foals. Appropriate hoof care is also important in managing and preventing flexural deformities.
    Author: Doug Thal DVM Dipl. ABVP


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