Through their lifetime horses can accumulate a number of injuries — cuts, scrapes, scratches and bruises. Most locations on the horse’s body are fairly forgiving of such injuries, however, there are a few sites on the body where added vigilance is necessary to ensure a favourable outcome. An injury to an eye or a joint is readily recognizable as serious. An injury to the coronary band and/or coronet is equally serious yet is often overlooked as such.
The coronet or coronary band refers to the area on the horse where the hairline meets the hoof capsule. This structure is responsible for continuous hoof growth over the horse’s lifetime. When the coronary band is injured, in any way, the future growth of a horse’s hoof wall is jeopardized. The coronary band of the horse is like the cuticle or nail bed of a human finger. This is the germinal centre that actively makes new cells, and so the growth of the hoof wall depends on the viability of these cells.
Inside the coronary band is the coronary corium, a blood-filled tissue which generates and feeds the hoof wall. New hoof wall cells produced in the corium gravitate downward from the coronary band in a spiralling configuration, giving the hoof wall its framework of strength and elasticity. Any interruption in this growth pattern will disrupt the integrity of the hoof wall. As a sequelae, the appearance and sometimes the functionality of the hoof wall is affected. Hoof wall defects as a result of coronary band injuries will run vertically from the site of injury. These defects can take the form of a cosmetic deformity such as a blemish, a crack, a fissure or a depression in the hoof wall. If severe enough, the cracks and fissures risk becoming inflamed or infected and can lead to lameness.
Horses sustain coronary band injuries following a number of unfortunate events. Entanglements with wire, and collisions with fences, metal sheds, old equipment, or trail debris to name a few. Coronary band injuries also commonly occur during trailer loading and/or while the horse is travelling in a trailer and attempting to negotiate its footing during travel. Further means of harm can come to the coronary band when horses overreach — when the back hoof connects with the foreleg below the pastern. This misstep can happen during training or with high-speed sporting events such as barrel racing, reining or jumping. The incidence of “clipping” the pastern and coronet is further increased during takeoff, landing and striding when corks are placed in iron shoes.
The treatment for coronary band injuries depends upon the severity of the injury. If the injury is not too serious, it may be gently cleaned with water and kept wrapped for the period of time necessary to heal. It becomes very important to keep this area as clean as possible for it offers the body the best chances of successfully resolving the injury with the least amount of permanent damage to the hoof wall. Injuries to the coronary band often bleed profusely due to their rich blood supply. Therefore bleeding may need to be controlled with a clean pressure bandage. A hospital bandage applied to the foot offers the wound the best opportunity to heal. Such a bandage may seemingly appear to be “in excess” yet an investment in “overcare” with injuries in this particular location is worthwhile.
More serious injuries may require veterinary exploration to assess the level of damage.
Debridement, surgical repair, or followup casting of the foot for a period of time may be necessary to minimize complications and improve the final outcome.
The close proximity of these wounds to the ground surface places them at a greater risk for contamination, and so the need to keep them bandaged while healing is pertinent. Healing is further challenged by the loading and unloading of the hoof which results in constant movement of the healing tissues. Therefore, an equally important part of healing coronary band injuries is proper trimming of the hoof. By sparing and easing the forces of weight bearing, proper growth from the coronet is encouraged.
Measures taken to prevent coronary band injuries include policing the horse’s environment for safety as well as acknowledging high-risk situations for injury. These include trailering, early stages of training where foot placement by the young horse can be awkward, and specific competition demands. Bell boots, which cover the coronary band, worn at these times will often avert injuries. Horses improperly trimmed or shod will also be at a greater risk for injuries to this vulnerable site due to increased chances of overreaching.
Early recognition and proper care of coronary band injuries favour a positive outcome for the healing process, and mitigates damage to this particularly sensitive tissue.