Q: My horse recently suffered a puncture wound through the frog of his foot. Under my veterinarian’s direction I’m bandaging the foot each day to keep the wound dry and prevent infection as it heals. Because I can’t really see the wound, how do I know it’s healing well? Are there any complications that I should be concerned about?

A:  Puncture wounds of the sole and frog by nails, screws, or other sharp objects are common hoof injuries in horses. The penetrating object might be contaminated with soil, manure, or rust, which can lead to infection. Clinically, puncture wounds can be misleading, because they can appear small and insignificant, and aggressive medical therapy or appropriate surgical treatment might be delayed until signs of infection or lameness occur.

Depending on the depth and location of the puncture wound, several hoof structures can be affected.  Puncture wounds are critical injuries if anatomical structures such as the coffin (third phalanx) bone, coffin (distal interphalangeal) joint, digital cushion, deep digital flexor tendon, navicular bursa, or navicular bone are involved. Deep puncture wounds of the sole and middle third of the frog are emergencies and should be treated aggressively to prevent infection of bones, joints, and soft tissue structures in the hoof. These cases are challenging to treat and should be referred to an equine hospital for surgical treatment, if needed. 

Wound management and treatment options are based on the location, depth, and direction of the penetrating wound. Minimally invasive penetrating sole and frog injuries can be managed conservatively with broad-spectrum antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), tetanus toxoid, hoof soaking, and bandaging treatments. If the injury appears to penetrate deeper hoof structures, such as the navicular bone or bursa, deep digital flexor tendon or sheath, or coffin joint, then the horse should be promptly referred to an equine hospital for more aggressive treatment, such as surgical curettage and wound lavage. The “street nail” surgical procedure is used to create a surgical window or fenestration between the frog surface and navicular bursa, thereby promoting adequate wound drainage and allowing for subsequent treatment of the affected area. Surgical management can also involve the use of supportive care, antimicrobial and anti-inflammatory treatments, wound care lavage techniques, sterile bandage changes, and a medicine plate shoe to promote healing.

Consult your veterinarian for supervision regarding the clinical care and resolution of penetrating hoof wounds. Their assessment will consider the horse’s overall condition and time since initial injury, treatment protocol, soundness evaluation, wound healing complications, and diagnostic imaging and laboratory findings. Ongoing clinical evaluation is needed to direct patient management decisions, such as when to adjust the use of antibiotics and anti-inflammatory medications, wound care options, and bandaging. With hoof puncture wounds, some of the complications, such as lameness, swelling, heat, and infection occur when the sound surface hole seals over underlying pathology, restricting draining. Therefore, veterinary care is needed for ongoing supervision and intervention.

The prognosis for penetrating wounds of the hoof sole and frog is guarded but generally, those horses that have fewer deep structures involved and receive timely and appropriate treatment experience more favorable outcomes.