Healing quarter cracks
The most common type of hoof cracks, quarter cracks are treatable with patchingA hoof crack, which interrupts the continuity of the hoof wall, can be a significant detriment to the proper functioning of a horse. Hoof cracks typically begin either at the coronary band and extend downward or at the weight-bearing surface of the hoof extending upward, and their location and severity directly affect their impact on a horse's performance. The most common cracks are quarter cracks, which occur at the quarter, the thinnest and most delicate part of the hoof wall.
Quarter cracks are caused by a variety of factors, including genetic predisposition, time of year, improperly trimmed feet, and traumatic injury. Injury to the site may be the result of common things such as hard racetracks, misplaced shoeing nails, and stones. Cracks may also develop when horses are exercised on uneven surfaces. Many quarter cracks are the result of an infection around the frog or in the heal area.
Since quarter cracks are usually a recurrent and lifelong problem, the causes are less important than the care and treatment. Left untreated, a quarter crack may take several months to heal, but the economic restraints placed on the competition horse make it virtually impossible to allow a sufficient amount of time for natural healing to occur.
Treatment of a quarter crack involves immobilization and stabilization of the crack and alleviation of pressure from the weight-bearing surface of the hoof (from the crack to the heel). There are various techniques for repairing hoof cracks. In the past, patching techniques have included nailing, wiring, or screwing the edges of the crack together. Gluing vulcanized rubber to the cracked wall was a primitive variation of current patching techniques and a precursor to modern fiberglass and acrylic techniques, while more state-of-the-art patching materials involve glues and resins.
Hoof cracks in competition horses (where time is of the essence) and infection or extensive cracks require a high degree of immobilization. The fiberglass patching technique produces the best method of immobilization and is the preferred method of patching in these instances. Although this method provides the strongest type of repair, it is technically complex and requires a great deal of expertise for its correct application.
Although acrylic and glue/resin techniques are valid methods, they should not be used if infection is present. These methods will seal in any infection in the hoof tissues applied to infected cracks, they often incite further inflammation of tissues, and may aggravate lameness.
Despite popular misconceptions, most quarter cracks originate from a localized infection of the hoof. In order for the hoof to heal, the infection must be treated and the crack must be immobilized. The infection usually can be treated by surgical removal of the infected wall and application of an antiseptic solution. Stubborn cases, or instances where schedule constraints limit time, may also require painkillers and antibiotics.
The recommended fiberglass patching method to repair quarter cracks involves:
- Initial examination of injury site, starting with the removal of the shoe.
- Dissection of the crack and trimming of heel to eliminate pressure. This step should only be performed by qualified individuals.
- Drilling of one-eighth-inch holes (approximately three-sixteenths of an inch deep) in the hoof wall in a pattern that enables maximum strength and also allows for placement of the shoe. Holes must be placed at least three-quartes of an inch below the coronary band. Correct placement of holes is difficult, especially in a thin-walled hoof, complicated crack, or multiple cracked hoof.
- Covering the defect with protective plastic to prevent sealing of the crack and to allow air and medication to reach the infected tissues.
- Attachment of fiberglass cloth with blunted sheet-metal screws.
- Saturation of the fiberglass patch with epoxy resin and hardener.
- Covering the area with an additional protective (fiberglass) patch.
- Bandaging the foot and allowing sufficient time to set.
- Removal of the bandage and trimming to duplicate the missing hoof wall.
The fiberglass patch may remain in place until natural hoof growth negates its need and enough time has elapsed to allow for the regeneration of a healthy hoof wall. A veterinarian will be able to advise on the healing of the underlying sensitive laminae tissues as well as the necessity of applying any medications. A knowledgeable farrier should be able to trim the patch with normal shoeing equipment.
It is not uncommon for a patch to remain intact for several months, but it may be advisable to reapply a patch once the original crack has grown down sufficiently. The application of a second patch at the original injury site can be a precautionary measure against a new quarter crack. This is often the case when the crack is uncertain, when there is a genetic predisposition toward hoof cracks, or when the economic viability of a competition horse is an issue.
Most importantly, the horse's normal workout program should be resumed after the patch has set. Exercise stimulates circulation and increases blood flow to the affected tissues, thereby promoting healing.
Immobilization of a crack is not easy to accomplish and, unfortunately, there is no material available that duplicates the living hoof wall. Overall, fiberglass is perhaps the most reasonable option, as it provides the most strength and allows for conditions favorable to healing.
Healing a quarter crack is best accomplished by using an experienced veterinarian and farrier. Treated with the appropriate technique, quarter cracks can be dealt with in a way that results in the best healing and least loss of time. No method is perfect and no material is ideal, but we have come a long way in the treatment of quarter cracks.
Judson L. Butler, D.V.M., has treated such runners as Unbridled's Song, Slew o' Gold, Afleet, and Sultry Song, among others. An equine veterinarian specializing in hoof and lameness problems, Butler resides in Manorville, New York.