Foiling is a minor surgical procedure employed to correct ANGULAR LIMB DEFORMITIES in foals. It is almost always used in conjunction with CORRECTIVE TRIMMING of the feet.
The technique provides the veterinarian with a means of manipulating the foal's bone growth in an attempt to straighten a "crooked" limb. Specifically, foiling is intended to accelerate growth along the "short side" of a long bone. The concomitant difference in growth rate between treated and untreated surfaces of the bone results in eventual straightening of the limb.
The technique entails the infusion of counterirritant (typically 2% iodine in almond oil) within the periosteal tissue lining the concave (shorter) bone surface. Increased irritation and blood flow resulting from the counterirritation increases activity within the adjacent growth plate, thereby accelerating its growth.
An increased growth rate allows the length of the bone's "short side" to approach that of its "long side", thereby resulting in comparable lengths between the two sides and a straighter bone.
The procedure is performed in the standing/ sedated foal. On average, three treatments are administered at 3-week intervals.
The distal aspect of the radius (to correct angular deformation of carpus) and the distal aspect of the cannon bone (to correct angular deformation of the fetlock) are the two most common sites for foiling.
It is important to implement this technique during the time when bone growth manipulation will be most effective:
- Radius: 6-18 months of age
- Cannon Bone: 3-9 months of age
Multiple limbs and multiple sites on each limb can be "foiled" simultaneously. Moreover, no change in the foal's turnout schedule nor exercise routine is necessary before, during or after the treatment period.