Four types of hoof wounds and how to treat them
A horse’s hoof, with its solid exterior, can appear impenetrable to the uninitiated. But wounds do occur at various depths and severities in the hoof and surrounding tissues, and they can be challenging to treat. They lie close to the ground, with all its various contaminants, and the injured structures are constantly in motion. Key to resolving hoof wounds is cleaning them appropriately, relaying information about them to your veterinarian and getting them assessed, and managing the lesion carefully until it resolves. In some cases, not following the right protocol can mean long-term struggles with lameness.
Here are four types of hoof injuries and how to manage them.
But First: Clean and Examine
Upon discovering a hoof wound, the first step is to clean it enough to determine the extent of the injury. If the hoof capsule is intact or a puncture is not yet open, Andrew Parks, MA, Vet MB, MRCVS, Dipl. ACVS, head of the Department of Large Animal Medicine at the University of Georgia’s College of Veterinary Medicine, in Athens, suggests using a wire brush to remove debris.
“A wire brush is too traumatic for underlying and exposed soft tissue, so it’s best to pursue other cleaning methods in those cases,” he says.
Next, use a soft fiber scrub brush to further clean the surface so you can get a better look at the insult.
Ray Randall, DVM, of Bridger Veterinary Clinic, in Montana, sees many lower leg and hoof wounds caked in mud and manure. For these he suggests using a water hose for initial cleaning: “It’s best not to use the nozzle, as that amount of water pressure can drive contamination deeper into the wound. Once the bulk of debris is removed, scrub the hoof with tamed iodine or chlorhexidine scrub, and rinse well.”
On the whole, says Parks, “the hoof is the skin of the foot so, with respect to how the tissues heal, whatever is done to wounds of the skin elsewhere is likely to be appropriate for the foot.”
Randall emphasizes the importance of understanding basic lower limb anatomy terms (see TheHorse.com/154142) before a hoof emergency happens, so you can help your veterinarian grasp the problem at hand when it does.
“Communicate a succinct description of the wound to your veterinarian,” says Randall. “Follow up with a photo sent by e-mail or text so your vet can determine the urgency for (tending) to the horse.”
After a thorough physical exam of the hoof, your veterinarian might deem some hoof injuries, such as a mild overreach injury of a heel bulb or the hoof wall broken out near old nail holes, less serious than others and unlikely to have a harmful long-term effect.
“Mild abrasions of the hoof capsule or coronary band that never reach underlying layers tend to heal quickly with little intervention other than routine cleaning,” says Parks.
1. Broken Hoof Wall
As the hoof wall grows down and out, the foot might prune itself on the ground and hard surfaces, causing pieces to break off. Or, the horse pulls a shoe, resulting in the same. “A lot of hoof wall can be missing, yet a horse does just fine,” says Randall.
“As long as a piece of hoof wall that pulls away with the shoe is confined to the hoof capsule (and not compromising the tissue above or within it), it usually grows out normally,” adds Parks. “It may be a nuisance that needs patching until the wall has grown down.”
Farriers can choose from various products to patch hoof wall defects. However, “it’s important to consult your veterinarian before a farrier applies a hoof patch,” Randall says. “A deep defect that involves laminar tissue might harbor bacteria that fester when sealed beneath a hoof patch.”
Make sure exposed soft tissues have begun to keratinize (harden) before placing a patch, Randall says. Remove the patch if your horse becomes lame suddenly.
If the missing hoof wall involves underlying dermis (the layer beneath the outer hoof horn) or subcutaneous (beneath the skin) or even deeper tissues, apply a bandage and allow the wound to heal with granulation (scar) tissue and epithelialization (skin or hoof horn replacing granulation), says Parks.
2. Coronary Band Injury
The coffin joint’s location beneath the coronary band makes it vulnerable to penetration by sharp objects and resulting infection. With that in mind, have your veterinarian evaluate wounds to this area immediately if they appear more than superficial. Other vital structures that could be involved include the collateral cartilage on either side of the coffin bone and, with severe, deep wounds, the navicular bursa (the sac cushioning the navicular bone) and/or deep digital flexor tendon, which both lie behind and beneath the coffin bone.
Randall says significant coronary band lacerations can lead to permanent hoof cracks that you must manage over the course of the horse’s life.
The more immediate and aggressive the veterinary care, the better the chance of a favorable outcome, says Parks. “Deep injuries to the coronary band may result in loss of the coronary germinal epidermis (the outermost skin layer that’s still in the early stages of development) that forms hoof tubules (the “grain” of the hoof wall),” he says. “Interruption of the germinal cell layer is likely to lead to permanently altered structure and strength of the hoof wall below the injury.”
3. Penetrating Injury
Horses occasionally step on nails and sharp objects, with the potential to penetrate the sole. If the horse can stand flat-footed, leave it alone until the veterinarian arrives. Do your best to keep the horse from moving, or at least protect the punctured area with cotton or combine roll and a bandage, says Randall.
“If there is concern that a nail is long and deep and could penetrate further (if the horse were to stand flat-footed), take photos of the embedded nail from the side,” he says. “Pull it out and mark the depth of penetration on the nail with a file or Sharpie pen—the portion of the nail that was lodged in the foot appears moist.”
In most cases, it’s best to have your veterinarian come to the farm as soon as he or she can to evaluate hoof penetration depth and treat any contamination.
“When possible, it helps to have radiographs with a nail in place,” says Randall. “However, this only shows the depth that the nail is at that time; it may have penetrated deeper initially as, for example, a horse steps on a nail with a board attached and, as he pulls the foot back, the nail is extracted a bit by the board.
“If a nail must be pulled from the foot before veterinary attention arrives, then your vet has other means to examine the depth of the puncture,” he adds. “The horse is sedated, given a regional anesthetic nerve block (to numb the area), and then a metal probe is inserted and radiographs taken to determine the extent of the wound.”
Contrast radiography (infusing radio-opaque dye into the nail hole and taking X rays) further reveals the nail tract’s depth.
A nail in the frog, particularly the cleft of the frog (the triangle-shaped area in the center), can put a horse in considerable danger. If it only penetrates slightly, it might not become a significant issue. But a nail that enters and contaminates the navicular bursa, deep digital flexor tendon, and/or coffin joint can cause fatal injury. If the horse is in danger of putting weight on the foot and driving the nail deeper, again, take photographs, pull it out, and mark its penetration depth. Depending on the injury’s severity, your veterinarian might need to take MRIs or perform surgical exploration, says Parks.
In less extreme cases wood or wire might become embedded in the hoof. “You might see a tiny disruption in the hoof or a little blood around the coronary band,” says Randall. “Closer scrutiny might reveal a foreign body sticking out. Leave it in the hoof wall or coronary band until your vet arrives. What may seem like a small item could end up being a large chunk of wood or metal that needs to come out whole.”
This is best done by a veterinarian, with the horse sedated.
4. Hoof Abscess
With a hoof abscess, your horse might seem perfectly fine yet become non-weight-bearing on a leg two hours later. It is important to communicate to your veterinarian the extent to which he’ll weight the leg. Normally, a fracture is too painful for the horse to bear any weight, whereas with a hoof abscess he might still touch the limb to the ground briefly. If the abscess is in the rear portion of the hoof, for example, he might step quickly onto his toe with his heel raised off the ground.
“If you see your horse hobbling around very acutely lame at the walk, pick up the foot, clean it well, and look for a nail,” says Randall. If you don’t find anything, push on the heel bulbs and coronary band because a foot abscess often tries to break out at one of these paths of least resistance; an affected horse will react to finger pressure at the sensitive area.
Parks agrees that many horses with hoof abscesses develop acute lameness with no history or sign of an external injury. The foot might feel warm, and the horse might resent rapping on the hoof wall with a hammer or pliers. Some abscesses are too deep within the hoof to affect outer soft tissues but respond to hoof tester pressure over the inflamed area of the sole or wall.
“Poultices and foot soaking are useful to soften the sole and coronary band to facilitate natural drainage,” says Parks.
On occasion, a hoof abscess can cause swelling of the soft tissues that extend into the pastern and up the rear tendons of the cannon bone—this can mimic a tendon injury. Once the abscess opens and drains, however, the swelling abates.
“If hoof testers isolate a sole abscess that is accessible from the bottom of the foot, then it is important (for a farrier or veterinarian) to open it for drainage,” says Randall. “The infected area is dug out enough that it drains sufficiently and doesn’t plug up and require another veterinary visit to reopen it.”
Generally, basic hoof abscesses, especially those open for drainage, don’t require systemic antibiotics.
Wound Care and Bandaging
If your horse suffers any type of hoof wound, check your records to make sure he received a tetanus immunization within the past six to eight months. Your veterinarian likely administered this as part of your horse’s annual core vaccines. If not, have your vet back out to give the vaccine immediately.
Because hoof wounds are in proximity to the ground and its massive contamination potential, it’s important you keep them clean and dry.
“Bandage stuff out, not in,” says Randall. “Put the horse on a clean rubber mat or concrete for bandage application.”
Cover the wound with a nonstick pad, then wrap the foot in bandaging tape; you can attach elastic cloth tape with adhesive (e.g., Elastikon) directly to the hoof wall, over padding (cotton or combine cotton pad) that protects the coronary band and pastern soft tissue. Figure-eight the tape over the heel bulbs to keep the bandage from riding up. The objective is to put the bandage on snugly enough that it stays put but does not apply undue pressure over the coronary band, says Randall. The top of the bandage should end either on the upper pastern or include the fetlock to help keep out shavings and other debris.
“Don’t turn a horse out in muck or mud when the foot is bandaged,” he says. “The foot needs to stay clean and dry, especially in the early stages of managing a hoof wound.”
He says you can reinforce a bandage with materials such as Gorilla tape or Nashua 557 duct tape, which are tough, durable, and super sticky.
Some horses do better with a hoof boot (such as an Easyboot) over the bandage. This can keep the hoof and bandage clean and dry and allows the horse to be turned out, provided the boot fits well and stays on. Remove and replace the boot daily to make sure shavings or dirt don’t accumulate beneath the foot. If there is room to put a light layer of cotton in the bottom of the boot, the material will absorb moisture and help keep debris out.
Bandage change frequency depends on wound severity. Prior to granulation tissue formation (which can take anywhere from three days to three weeks, depending on the wound’s cleanliness and size) Parks says he typically likes to change the bandage daily. Randall agrees that daily changes are important initially, as the wound produces a lot of exudate (fluid) in this stage. Smell the bandage when you remove it; it shouldn’t have a foul odor. Lack of odor is a good sign that there is not an infection. Once the exudate subsides, you can keep the wound bandage on for three to seven more days, as long as it stays tidy, dry, and in place. Reinforce the bottom of the bandage if it shows wear. Randall says the frequency of bandage changes also depends on the horse’s living conditions and the diligence of stall cleaning, because a bandage soaks up urine and manure readily.
Watch for improved soundness and signs of wound healing: “The development of granulation tissue at the base of the wound is the first stage of healing,” says Parks. “Encroachment of new hoof at the periphery of the bed of granulation tissue is a sign of continued healing. These steps occur as a steady process.”
Granulation tissue in a wound or sole abscess should be pink and healthy in appearance, also with no odor at bandage changes. It’s normal for granulation tissue to bleed initially, but tissue that continues to bleed after a lengthy period might indicate infection or poor healing. Normally, granulation tissue at the sole or hoof wall dries up, darkens, and hardens over a couple of weeks.
Serious and complicated hoof wounds with deep-seated infections are candidates for distal limb perfusion, in which the veterinarian administers antibiotics into the lower limb veins with a tourniquet in place to treat a broad area of the foot.
When you discover your horse has a hoof wound, clean away mud and debris to evaluate the injury. Talk to your veterinarian about next steps. Not all hoof wounds are serious enough to require veterinary attention, but it is best to err on the conservative side because the vital structures within are easily injured.