GETTING STARTED on the RIGHT FOOT TRACY A. TURNER | DVM, MS, DACVS, DACVSMR * Images Courtesy of Dr. Steve O'Grady
Introduction “No foot, no horse” is a common phrase indicating the importance of the hoof to the mature equine athlete. But it is decisions and management concerning feet and limbs during the first 2 years of life that produce a strong foundation for the animal’s future athletic career. Unfortunately, not all recognize the importance and influence of hoof care during this period as affecting the horse’s longterm future. This manuscript will focus on routine farriery in young horses and those limb deformities that can be addressed through farriery.
Evaluating the Hoof Good record keeping is important. Records are designed for the individual needs of the farm/owner and should reflect the physical appearance of a foal's feet and limbs at birth and any subtle changes that occur during development, on at least a monthly basis. Digital images (pictures and radiographs) can be taken and added to the foal's record. Pictures are very helpful in determining changes in the foal’s feet/limbs. Foals should always be observed walking each time they are trimmed. The author prefers to observe the foal walking before the feet and limbs are examined. Watching the young foal walk can be challenging as it seldom walks in a straight line. This can be remedied by walking the mare along a fence or wall and letting the foal walk alongside or follow the mare. The foal is observed as it walks toward and away from the examiner. Here the foal is evaluated for any lameness that may be present, the pattern of the foot flight, how the foot breaks over at the toe and how the foot contacts the ground. When examining the feet and limbs from the front, it is useful to use imaginary lines through the bones. This way, it is easy to see if, and/or where an angular limb deformity exists. However, one must be careful to note the presence of a rotational deformity. In these cases, both carpi are rotated outward, leading to a toe out or splay‐footed conformation, yet axial alignment of the limb forms a straight line. The coronary band is observed to see if it is level or parallel with the ground. Examining the feet and limbs from the side should note whether the carpus is flexed or hyperextended. The hoof‐pastern axis is evaluated to determine if it is aligned and not broken forward (flexural deformity) or broken backward (flexor flaccidity). Any swellings along the limb or involving the physis are noted and recorded. Each deformity is noted and should be scored on a scale of 1‐5; grade one being mild, while grade five is severe. Finally, the foot is evaluated off the ground, observing its position relative to the bones of the digit, symmetry of the foot, and the integrity of the horny structures of the foot. The above examination enables the examiner to evaluate the feet, limbs and movement in a systematic manner.
6 The Practitioner
Trimming the Foal:
Birth to One Month. At birth, the foal's hoof is enveloped in a gelatinous perioplic membrane which reduces the risk of trauma to the mare's reproductive tract during birth. Shortly after birth, with the first steps of life, the perioplic membrane on the solar surface of the foot wears and retracts proximally on the hoof wall and dries out. The foal's foot will be tapered, being wider at the coronet and becoming narrower distally at the ground surface. A foal's foot does not only grow in a distal direction, it also expands. As the foal's feet are tapered, expansion occurs proximally, and as the ground surface of the distal hoof is relatively small, the weight‐ bearing area is positioned dorsally. Exercise and trimming will enlarge the area on the ground surface of the foot and move it in a palmar/plantar direction. The pointed or tapered appearance will gradually disappear in the first few months of life. In foals with acceptable limb conformation, there is little need for trimming during the first month of life. One Month. Foals should be presented to the farrier at one month of age for routine trimming. All that will generally be necessary at this time is to square or roll the toe of the hoof to encourage the foal to break over in the center of the foot. At this age, due to the pointed toe, the foal may break over to either the outside or inside of the toe. This first farrier examination will also allow the foal to get used to having its feet handled. The farrier should be patient and the trimming procedure should be performed as gently and efficiently as possible. Two to Six Months. In the first few months of life, attention should be directed toward the structural integrity of the foot (foot mass) rather than to cosmetics. The important issues here are to promote the growth of thick, durable hoof wall, to ensure maximum sole depth in order to protect the vulnerable sole wall junction and developing distal phalanx, and to develop the structures in the palmar/plantar section of the foot. The structural mass of foot, defined as a strong hoof wall, adequate sole depth and a solid heel base, is vital for future soundness. It is the opinion of many authors that a hoof pick, wire brush and a rasp are the only tools necessary to trim foals that are kept on a monthly schedule. The goal is not to have the foal walk entirely on the hoof wall, but to load all the structures on the bottom of the foot. This makes the foot load sharing. Foals that are trimmed frequently and have a lot of horn removed tend to develop weak fragile hoof walls. Dr. Steve O’Grady has described an excellent technique for trimming these foals. Dirt and debris is removed from the foot using a hoof pick. The bottom of the foot is then cleaned vigorously using a wire brush to remove any loose exfoliating horn. Otherwise, the ground surface of the foot and the frog are left untouched. This affords the foal ample protection on the ground surface of the foot. Exfoliating horn from the sole will be continuously shed through an abrasive mechanism with Issue 2 • 2015