A foal with a club foot may still have athletic potential, provided treatment is early and appropriate, says Elizabeth Barr MRCVS
Club foot is more correctly described as a flexural limb deformity of the distal interphalangeal (coffin) joint.
This means the affected foal bears weight on the toe, often with the heel elevated from the ground. The hoof wall is more vertical than normal and in severe cases, the angle of the hoof wall may progress past the vertical.
A club foot occurs as the result of excessive pull of the deep digital flexor tendon (DDFT) on the pedal bone. The condition can be either congenital or acquired and is more common in the forelimbs.
In congenital cases, the foal is born with the deformation. Exactly why this happens is unknown, but causes such as genetics, poor positioning of the foal in the womb and exposure to agents or infections that affect normal foetal development have been suggested.
In acquired cases, the foal is born with a normal limb, but subsequently develops the deformity — commonly between one to six months of age. The reasons why this happens have not been proven, but phases of rapid growth (in turn influenced by genetics and feeding practices) and pain resulting from concurrent lameness have been implicated.
Pain from the flexural deformity itself can also result in a vicious cycle which exacerbates the problem.
Acquired club foot tends to occur in only one leg, although the opposite limb may be affected to a lesser degree. Where the condition is congenital, both limbs may be affected.
A foal with a congenital club foot should be treated early with physiotherapy (flexing and extending the limb to stretch the tendons) and intravenous oxytetracycline.
In most mildly affected foals, the deformity will quickly resolve. Severely affected foals can be more problematic to manage, particularly if the foal can’t stand without buckling forward which makes walking and feeding difficult.
In these more severe cases, bandaging, splinting or casting of the limb may be necessary. However, this is usually avoided unless absolutely required, due to potential complications with pressure sores.
Treatment options for foals with acquired club feet include: controlled exercise, trimming of the feet with lowering of the heel, application of a toe extension shoe, anti-inflammatories to treat any underlying pain; and limitation of dietary intake where this is excessive, including weaning the foal as appropriate.
Where the foal has a severe deformity or does not respond to medical treatment, surgery is required. Most commonly, the accessory ligament of the deep digital flexor tendon (the inferior check ligament, sometimes known as the AL-DDFT) is cut.
This increases the length of the tendon and muscle unit and decreases the pull of the DDFT on the pedal bone, therefore correcting the deformity.
Improvement is usually seen immediately, although foals should also receive farriery, anti-inflammatories and controlled exercise after surgery.
Prognosis for future athletic function after this surgery is good. Some scarring or swelling at the surgical site is to be expected, but this is normally only a cosmetic issue.
In very severely affected foals, cutting of the AL-DDFT might be insufficient to correct the deformity and cutting of the DDFT itself may be required. Where possible, this is avoided because prognosis for future athletic function is reduced and the complication rate is higher, compared with cutting the ligament.
Ref: Horse & Hound; 28 May 2015