Ask The Vet: Podiatry (shoe fitting, balance)

Question: My horse is barefoot and I’ve noticed that over the last few months his collateral groves aren’t the same depth on either side of the frog on the same foot (fronts only). There is more bar growth on the side with the deeper collateral groove. My trimmer doesn’t seem concerned, but I am worried the feet are out of balance. Are uneven collateral grooves a sign of imbalance?

Answer: First let me commend you for being observant and recognizing the asymmetry in your horses’ feet. Yes, uneven collateral grooves (sulci) may be a sign of imbalance. Particularly you indicated that the bars were longer on the side of the deepest sulcus which indicates to me that there is a static and geometric and/or dynamic medial-lateral imbalance in the limb or foot. In respect to horse’s limbs, static and geometric balance is generally interdependent. Static balance simply means balance at rest and is an indication of the alignment of the bones in horse’s legs and the symmetry of the hoof capsule around the distal phalanx (coffin bone). Ideally, a plumb line dropped from the point of the shoulder should bisect all the bones and joints of the limb and the hoof capsule when viewed from the front of the horse. Geometric balance is an indication of symmetry between two sides or halves of an object. For instance, in a horse with ideal limb conformation, each side of the previously mentioned plumb line should be equal and measurements of the same points along each side of the limb (medial and lateral) should also be equal. For example, if the plumb line bisects the cannon bone, the pastern and the hoof equally then the distance between the coronet band and the fetlock joint should be the same on both the medial and lateral side. Static and geometric balance may be evaluated with your horse standing on a flat level surface and applying a plumb line and ruler to various parts. Dynamic medial-lateral balance refers to how the horses hoof lands and loads during locomotion. To evaluate your horse’s dynamic balance, choose a hard level surface such as a concrete or asphalt barn isle or driveway to work on. Have someone walk and trot the horse away from you and towards you in a straight line. As the horse moves focus on the feet as they land. Horses with ideal limb anatomy and balanced hoof capsules generally land with medial-lateral symmetry, which is to say that both the medial and lateral heel will make contact simultaneously. Improper dynamic balance may lead to torsion or a twisting force inside the hoof capsule and uneven loading of joints. A video recording of the horse in motion may prove helpful for evaluating dynamic balance and radiographic examination may provide a more specific means for evaluating static and geometric balance.

It is important to note that there are various means of evaluating balance and “hoof balance” does not have a singular, inherent meaning. Also, asymmetry and imbalance are a very common finding in many productive and sound horses. Often it is necessary to find the proverbial “happy medium” between nature, balance and function.

My advice: Let your farrier know that you are curious and possibly concerned with your horses hoof balance. Your farrier likely understands the aforementioned information on balance and would be happy to assess your horse with you. If there are no significant findings and your horse is sound and performing up to expectations, continue to monitor and make adjustments as necessary. Adjustments may be as simple as changing the trimming frequency, changing the trim technique (removing more hoof wall on one side than the other) or therapeutic shoes may be required.

Courtesy of AAEP