High-power Photobiomodulation Therapy in the Conservative Management of Two Severe Equine Distal Limb Injuries

Abstract

Distal limb injuries in horses often carry a guarded prognosis due to the frequent involvement of critical anatomical structures such as tendons, synovial sheaths, and hoof capsule. When surgical repair is not feasible because of financial, anatomical, or prognostic constraints, conservative protocols incorporating adjunctive therapies may represent a valuable alternative. Photobiomodulation therapy (PBMT) has recently gained attention as a potential adjunct to support tendon repair and wound healing.

This report describes conservative management of two equine patients with severe distal limb trauma, both treated with a multimodal protocol that included high-power PBMT. The first case was a 7-year-old sport horse with complete laceration of the superficial and deep digital flexor tendons and contamination of the digital flexor tendon sheath. Surgical repair was declined, and the horse received systemic antibiotics, anti-inflammatories, regional limb perfusion, external immobilization, and 30 PBMT sessions over 123 days. The second case was a 5-year-old pony mare with traumatic medial hoof wall avulsion and exposure of the distal phalanx. Management consisted of wound debridement, systemic antibiotics and anti-inflammatories, stall rest, and 35 consecutive daily PBMT sessions.

Both patients showed progressive wound healing without infection, dehiscence, or exuberant granulation tissue. In Case 1, sequential ultrasonography revealed tendon reorganization and healing of the digital flexor tendons, with complete wound closure after approximately two months and return to paddock activity after 12 weeks. In Case 2, wound contraction occurred at an average rate of approximately 1 cm per week during PBMT, with a marked deceleration after discontinuation of laser therapy; complete epithelialization was achieved by day 80. Hair regrowth occurred exclusively in PBMT-treated areas.

These two clinical cases illustrate that high-power PBMT, when combined with standard conservative measures, may support wound healing, tendon repair, and functional recovery in equine distal limb injuries where surgery is not feasible. Although limited by the small number of cases and absence of control, the consistent clinical course and temporal association with PBMT support the potential value of this modality as an adjunctive therapy. Further controlled clinical investigations are warranted to validate these findings and to establish standardized protocols for different equine soft tissue injuries.