Application and viability of full-thickness coronary band grafting in equids

Abstract

Summary: The aim of the study was to determine whether a full-thickness equine coronary band graft can be successfully applied to acute wounds with excision of the coronary band and secondly, to describe the use of coronary band excision for the treatment of a clinical case of painful, abnormal hoof growth in a mature horse. Using 5 equids, a pilot study was performed in order to determine whether a 4 cm 2 graft involving the skin and coronary band, on the dorsal midline of both front feet, could be transferred within and between subjects. A defect in one horse was left open as a control but was managed identically in all other respects. Limbs were immobilized in a fiberglass cast, from the ground to mid-pastern, for four weeks and subsequently monitored at pasture for nine months. After euthanasia, skin samples from the neck and surgical sites were submitted for genotype analyses. A clinical case of lameness due to a recurrent hoof crack in the hind limb, was subsequently treated by coronary band excision in the same manner as the experimental control horse. During the study all defects healed without complication and resulted in hoof horn production. There were no full thickness horn cracks and the vertical junction between the excision site (skin and keratinised horn) and parent tissue was contiguous. DNA analyses suggested that none of the grafts were accepted, despite all sites healing. The clinical case resulted in normal hoof horn growth and cessation of lameness following surgery. Coronary grafting in the horse did not result in graft take. Results suggest that removing affected horn and coronary band with subsequent immobilization could be a treatment for recalcitrant coronary band defects and abnormal horn production in the horse.