What you see. The starting point for addressing any equine health related issue is your observation.


Fetlock Sagging Low, Hyper-Extending (in Adult)


Anatomically, the fetlock joint is not really the horse's ankle at all. It is the metacarpo-phalangeal joint of the forelimb - the equivalent of your middle (upper) knuckle joint. (The hind limb fetlock is the equivalent of the middle metatarso-phalangeal joint at the front of your foot.)

The fetlock is an extremely dynamic and sensitive joint - a very high-motion, critical component of the intricate mechanism of the lower limb of the horse.

Abnormal sagging of the fetlock indicates weakness or loss of function of the suspensory apparatus of the hind limb. The most commonly implicated tendon associated with subtle dropping of the fetlock is the suspensory ligament. Cutting of the flexor tendons and suspensory ligament causes collapse of the fetlock to the ground.

There is a great range of normal conformation in horses. Certain breeds and individuals drop more in the fetlocks than others. Older horses commonly have sagging fetlocks, especially older brood mares that have had numerous foals. In younger horses and in Peruvian Paso horses, abnormally sagging fetlocks can be indicative of a connective tissue disease called Degenerative Suspensory Ligament Disease (DSLD).

  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If you notice worsening of the sign.
    • If there seems to be pain, swelling or lameness.
  • Code Yellow

    Contact Your Vet at Your Convenience for an Appointment
    • If you consider this a chronic and relatively mild problem that is not changing rapidly.
    • Even if the horse does not appear to be lame to you.

your role


What To Do

Assess the horse's general health using the Whole Horse Exam (WHE), paying particular attention to the fetlocks - degree of sagging, swelling and pain to raising and flexing the limb. Look for increasing lameness, inability to stand with a hind limb raised (resistance to the farrier), and increasing difficulty moving. Share your findings and concerns with your vet.

If you feel your horse's performance is suffering, the condition is worsening, or the horse is lame, rest the horse until your vet performs an evaluation.

your vet's role

Your vet can rule out DSLD as a diagnosis, and may recommend additional diagnostics to identify the cause.
Questions Your Vet Might Ask:
  • Do you see swelling of the fetlock area?
  • How is your horse moving?
  • If the horse is lame, how lame?
  • What is the horse's age, sex, breed and history?
  • Is the horse limping or lame?
  • Is the horse a Peruvian Paso or have Peruvian Paso breeding?
  • Does your horse seem in distress or pain?
  • When did you first notice this problem?
  • How old is the horse?
  • What are the results of the Whole Horse Exam (WHE)?
  • Is the horse treading or shifting weight back and forth on it's hind feet?

Diagnoses Your Vet May Consider

The cause of the problem. These are conditions or ailments that are the cause of the observations you make.

Very Common
Less Common
more diagnoses

Treatments Your Vet May Recommend

A way to resolve the condition or diagnosis. Resolving the underlying cause or treating the signs of disease (symptomatic treatment)

Very Common
more treatments

Author: Doug Thal DVM Dipl. ABVP