Angular limb deformities in foals

Angular limb deformities can be treated in various ways, depending on the severity of the deformity, says Dr Mac.

Angular limb deformities in foals
This photograph of a five-month-old foal clearly shows the deviation in both fetlocks. Photo: Dr Mac

Breeding a foal is a long-term investment. The mare and stallion must be carefully chosen, the service fee paid and the in-foal mare fed and cared for for over 11 months.

On the day of birth, after spending a lot of time and money on producing a foal, you may find that the foal has an angular limb deformity. In some breeds, instant euthanasia is suggested; however, there are alternatives. These depend on the type of limb deformity and its severity.

Angular limb deformity
Basically, angular limb deformity means that the foal or horse has crooked legs. To diagnose the condition, stand directly in front of the foal. Draw an imaginary line from the point of its shoulder to its hoof.

If the leg turns outwards or inwards at the knee (or hock in the hind legs) or fetlocks, the foal has an angular limb deformity. The area of ‘deviation’, where the leg turns away from the straight line, is where the ‘deformity’ occurs.

Sometimes foals are born with angular deformities, but if they are kept stabled for the first three or four days, the ligaments tighten up and the foals’ legs straighten.

True angular limb deformities are a problem with the growth plates in the affected joint.

So, if the foal is not better within three days, it is a good idea to consult your veterinarian.

The angle of the displacement, as well as the joint affected, will play a part in the treatment. If the angle of deviation is less than 3°, conservative treatment with corrective hoof trimming is suggested. This should be done under instruction from a vet or farrier.

However, if the deviation is between 4° and 6°, corrective trimming, building up the hoof as well as extra corporeal shock therapy are advised.

If the deviation is greater than 7°, your vet will suggest X-rays with the possibility of surgical intervention.

There is an important time-related aspect to be considered as well. The growth plates of the fetlock close a lot earlier than those in the carpus and hock. Trimming should start before the foal is two months old, or earlier in the case of the fetlock.

It needs to be continued until the foal is at least six months old. Trimming should also be done at least once a month.

Hoof extensions will have to be put on before two months of age, and the farrier must see the foal every six weeks until it is at least 10 months old.

Shockwave therapy can be done over the same period, under the guidance of an equine physiotherapist.

Early surgical interventions involving trans-section of the growth plate can be done from the first month in the fetlock and carpus, and later than four months if it is the hock joint.

For more severe deviations, more radical surgical interventions can be done up to 24 months of age. However, surgery is expensive and it may be more sensible to make a decision on euthanasia at weaning.

The market for horses is currently not good, and foals with angular leg deformities may not be able to be used for riding.

Dr Mac is an academic, a practising equine veterinarian and a stud owner.