Chronic Equine Distal Limb Wound: Treatment with Platelet-Rich Fibrin

Abstract

Background: Distal limb wounds are common in horses and are often associated with delayed healing, contamination, and exuberant granulation tissue, particularly when managed by second intention. Conventional treatment focuses on wound cleansing, infection control, and protection, but these approaches may be insufficient in chronic lesions. Platelet-rich fibrin (PRF) is an autologous biomaterial that provides a fibrin scaffold and sustained growth factor release and has been proposed as an adjunctive regenerative therapy. This case report aimed to describe the clinical applicability of PRF for 2^nd-intention healing of a chronic equine distal limb wound.

Case: A 15-year-old mixed-breed mare was referred with a 60-day history of a chronic wound located on the medial heel bulb of the left hind limb. According to the owner, the lesion originated from a laceration evolved with delayed healing and developed exuberant granulation tissue that was removed by surgical excision 15 days before referral. On admission, the mare was alert, presented a body condition score of 7/9, and showed mild lameness (grade 1/5). The wound measured 13.5 cm² and exhibited exuberant granulation tissue, focal necrosis, and purulent exudate originating from the frog and sole regions. Treatment consisted of routine wound cleansing combined with weekly application of autologous platelet-rich fibrin and protective bandaging. PRF was obtained from whole blood without anticoagulant and applied as fibrin membranes directly onto the wound bed. Wound progression was monitored weekly through standardized photographic documentation and image-based area measurement. Progressive wound contraction, improvement in tissue homogeneity, reduction of necrotic tissue, and enhanced vascularization were observed throughout the treatment period. After 4 weeks, the wound area had decreased by 79.3%, epithelialization was evident, no signs of infection were present, and functional healing was achieved without residual lameness.

Discussion: This case describes the favorable evolution of a chronic distal limb wound treated with conventional wound management associated with platelet-rich fibrin. Distal limb wounds in horses are known to present prolonged healing times due to reduced vascularization, increased contamination, and mechanical stress, frequently resulting in exuberant granulation tissue and delayed epithelialization. In this context, adjunctive regenerative approaches have gained interest as complementary strategies to conventional care. Platelet-rich fibrin is an autologous biomaterial characterized by a dense fibrin matrix that acts as a scaffold for cell migration and allows the sustained release of growth factors involved in tissue repair. In chronic wounds, this biological environment may contribute to modulation of persistent inflammation, angiogenesis, and fibroblast activity, supporting more organized healing. The consistent week-by-week improvement observed in this case, including wound contraction and tissue maturation, suggests that PRF may positively influence the wound microenvironment. Although the healing outcome cannot be attributed exclusively to PRF due to its association with standard wound care, the observed clinical progression supports its potential role as an adjunctive therapy. As a single case report, the findings are descriptive and cannot be generalized. Nevertheless, PRF preparation is simple, low-cost, and based on materials commonly available in equine practice, making it feasible for use under both hospital and field conditions. Within these limitations, this case highlights PRF as a practical adjunctive option for the management of chronic distal limb wounds in horses and supports further clinical investigation.

Keywords: Wound management, regenerative medicine, horse, lacerations, limb.