Using Foot Casts to Manage Laminitis 'Sinking' Cases

Using Foot Casts to Manage Laminitis 'Sinking' Cases

the benefits of using a foot cast to achieve this include stabilizing the entire foot, decreasing individual movement of the hoof capsule and bony column, and reducing shearing and twisting of the lamellar interface.

Photo: Raul Bras, DVM, CJF

Mechanical collapse, or "sinking," of the distal phalanx (coffin bone) is a devastating complication of laminitis. Prognoses for these cases are often poor, but foot casts might improve horses' survival rates if applied early in the sinking process. Raul Bras, DVM, CJF, of Rood & Riddle Equine Hospital's podiatry center, in Lexington, Ky., relayed his and colleagues' experiences using foot casts on laminitic horses at the 6th International Equine Conference on Laminitis and Diseases of the Foot, held Oct. 28-31 in West Palm Beach, Fla.

Simply put, laminitis is an inflammation of the laminae--interlocking leaflike tissues attaching the hoof to the coffin bone--that can strike any number of feet on any horse due to a variety of triggers such as high-carbohydrate diets to mechanical overload. When treating a laminitic horse, Bras' objectives for limiting coffin bone displacement include reducing the horse's body weight to lessen the load on the foot; ensuring weight bearing is shared by the sole and frog; redistributing weight bearing from the most stressed portion of the wall to the least stressed; and decreasing mechanical forces around the distal interphalangeal (coffin) joint. He explained that the benefits of using a foot cast to achieve this include:

  • Stabilizing the entire foot;
  • Decreasing individual movement of the hoof capsule and bony column--essentially making these a single unit;
  • Reducing shearing and twisting of the lamellar interface; and
  • Providing axial (inner hoof wall) support and ease of breakover in all directions.

To determine how effective foot casts are in treating displacement cases, Bras reviewed Rood & Riddle records from 2005-11 of 43 horses with laminitis secondary to a systemic illness (e.g., colitis, pneumonia) that were treated with foot casts. The majority of horses were Thoroughbred broodmares, but a variety of other breeds also were represented.

The horses were monitored initially for early clinical signs of displacement such as coronary band ledging, in which a ledge or depression can be felt in the soft tissue nearest the hoof wall. The treating veterinarian then performed subcoronary "grooving" in each animal's hoof wall about a half inch below the hairline to try to relieve pressure prior to applying a cast. He or she applied a sole support material, a felt pad (to avoid cast sores), Stockinette cotton cast padding, and fiberglass casting tape to create a cast encasing the entire foot and pastern. Once the cast was set the veterinarian applied a shallow dome made of acrylic material to the ground surface of the cast, allowing the foot to break over in any direction and focusing the load under the coffin joint.

Casts remained on the horses for about 30 days before removal and hoof reevaluation. The veterinarian reapplied each cast as many times as needed and removed it when displacement was no longer evident. Long-term follow-up on these horses continued for at least two years, and their outcomes were considered successful if they were pasture sound. Of these horses, 47% survived, which is a better-than-expected outcome, according to Bras.

Thus, "Foot casts are an effective technique to manage (coffin bone) displacement of horses with acute or early chronic laminitis," Bras concluded. "The whole idea is to prevent further damage."

About the Author

Alexandra Beckstett, The Horse Managing Editor

Alexandra Beckstett, Managing Editor of The Horse and a native of Houston, Texas, is a lifelong horse owner who has shown successfully on the national hunter/jumper circuit and dabbled in hunter breeding. After graduating from Duke University, she joined Blood-Horse Publications as Assistant Editor of its book division, Eclipse Press, before joining The Horse.

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