Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Inferior Check Ligament Strains or Tears

Synonyms: Accessory Ligament Deep Digital Flexor Tendon Desmitis (ALDDFT)


Injuries to the inferior check ligament are relatively uncommon. They generally appear as mild to moderate lameness with possible mild swelling in the back of the mid-cannon region of the lower limb. In other cases, the signs can be very subtle and only diagnosable using ultrasound or advanced diagnostics.

There is a poorly understood condition of ALDDFT desmitis in which there is knuckling of one or both hind fetlocks.

Ultrasound is the most useful diagnostic for diagnosis of this condition and to assess severity and healing.

Treatment is the same as other flexor tendon injuries, but in select cases the ALDDFT can be cut. For the syndrome of knuckling of the hind fetlocks, cutting of the ligament may be helpful in some situations.

my vet's role


For horses that injury the ALDDFT, the prognosis is fair to good with early diagnosis and treatment, and adequate rest and rehabilitation. With injuries of this type, re-injury is always a possibility.

For horses with knuckling of the rear fetlocks, the prognosis is guarded, and is improved with cutting of the ALDDFT.

my role

Questions To Ask Your Vet:
  • How did you reach this diagnosis?
  • What is the likelihood of recurrence given the amount of work I expect from the horse?
  • Will cutting of the ALDDFT help the condition?

Prevention involves adequate conditioning and training, good hoof care and shoeing. Select horses of good conformation and suitability for your intended use.

For the knuckling condition, the development of the condition is poorly understood , and so is prevention.

Author: Doug Thal DVM Dipl. ABVP