By Garrett Metcalf, DVM

There is a wise old saying, “No foot, no horse,” and that is absolutely true. Horses of all breeds, disciplines, and sizes must have healthy feet, or they will suffer from poor performance, chronic pain, or, worse, succumb to diseases of the foot. Several medical conditions require surgical treatment within the hoof wall of the horse, and this article will highlight the most common conditions that necessitate surgical intervention and specialty farrier care.

Foot Abscesses

Foot abscesses are a very common issue that nearly every horse may experience at some point in their lifetime. While abscesses are often minor issues that can be easily corrected by a farrier or veterinarian, allowing access to the abscess for drainage, they can also be debilitating and sometimes serious. Abscesses are localized pockets of infection that find their way into the sole or white line of the foot. These abscesses often form due to structural abnormalities in the foot, trauma leading to bleeding under the sole, improper hoof care that creates abnormal forces on the foot, or, of course, the old hot nail.

For example, trimming the foot without relieving enough sole pressure can overload the sole, leading to bruising and setting up an abscess. Other common foot abnormalities that lead to abscessation are laminitis and club feet. These conditions can cause tearing and stretching of the white line, allowing bacteria and moisture to enter deeper into the foot. In some cases, this can destabilize an already unhealthy foot, leading to a life-threatening situation. Deep abscesses that go untreated for days or weeks can continue to invade and dissect through tissue planes, forming larger abscesses. These large abscesses may require surgical intervention to prevent spreading and to eliminate the infection completely.

Pedal Bone Osteitis

The pedal bone, or coffin bone, is unique compared to other bones in the horse. It is a porous bone that is intimately attached to the foot capsule and sole. The bone and the hoof tissue have a high blood supply due to the vast amount of metabolic energy required to keep the foot supplied with nutrients. However, when the hoof is diseased or compromised by conditions like laminitis or infection, the blood supply can be jeopardized, leading to disaster. The resulting condition may be an infected portion of the coffin bone, or sequestration of bone.

Bone sequestrums occur when bone lacks blood supply and becomes infected by bacteria that thrive on dead tissue. While sequestrums are generally treatable, the coffin bone is unique in that it lacks an outer soft tissue coating called periosteum. This membrane typically provides blood supply and supports healing with progenitor cells and stem cells. The absence of this layer in the coffin bone leads to poor healing, a more delicate blood supply, and increased vulnerability to infection.

Treating an infected portion of the coffin bone requires aggressive action to prevent further spread and destruction. If infection spreads, it can damage the blood supply to the bone and hoof, weakening the bone to the point of fracture under the horse’s weight. The first step in treatment is aggressive surgical debridement or removal of infected tissue and bone. This is followed by aggressive antibiotic therapy using both local delivery methods (such as antibiotic beads, pastes, or ointments) and systemic routes. Regional limb perfusions, where antibiotics are delivered to the affected limb via blood vessels, may also be used. Additionally, proper support for the remaining hoof is essential, which requires the expertise of a skilled farrier.

Quittor

Quittor is a chronic deep infection within one of the collateral cartilages of the coffin bone. The collateral cartilages, which are attached to the coffin bone’s wings, are often referred to as “side bone” on x-ray films. Lacerations, puncture wounds, trauma, and abscesses can lead to infection in the collateral cartilage. While quittor might seem like a minor issue to most, it is often much more serious than it appears. This infection can smolder beneath the surface, not fully resolved until the infected cartilage is removed.

The diagnosis is typically straightforward, as there is often a draining tract with swelling, heat, and proud flesh over one of the collateral cartilages. However, the challenge lies in locating and removing all of the infected tissue. A hoof wall resection, or a window cut in the side of the foot, is often required to access the infected tissue and allow drainage and local treatment. Quittor can be challenging and may require multiple surgeries to clear the infection. After the hoof wall resection, a specialized shoe may be needed to protect the foot and help stabilize it until the hoof grows out to cover the defect.

Keratoma

Keratoma is a benign, tumor-like growth that arises from the hoof wall or laminar tissue of the foot, known as keratin. Keratin is the same material that makes up our hair and nails. This growth expands between the foot wall and the coffin bone, leading to pressure necrosis and damage to the coffin bone. Keratomas typically form at the toe region of the foot and are thought to be triggered by trauma to the hoof tissue.

The most common signs of a keratoma are recurring foot abscesses in the same location, accompanied by localized lameness. X-rays, CT scans, and MRIs can help diagnose the presence of a keratoma. Often, the growth is well-formed enough to be visible on x-ray, but advanced imaging may be necessary for a definitive diagnosis.

The only treatment for a keratoma is surgical removal through the hoof wall. This requires a hoof wall resection, performed with either an oscillating saw or drill bit, to remove the hoof wall without damaging the coffin bone. The keratoma typically appears as off-white, crumbly tissue that is easily removed from the surrounding healthy hoof wall. After surgical removal, a specialized shoe is required to protect the foot and allow access to the surgical site for continued treatment and to prevent infection.

Coffin Bone Fractures

Coffin bone fractures can occur in several patterns, some more serious than others. These fractures are typically categorized as either articular or non-articular, depending on whether or not the coffin joint is involved. Non-articular fractures are generally less serious and can heal without major surgery. These fractures are often stabilized with a special shoe and casting tape applied around the foot to make the hoof itself act as a splint for the coffin bone.

Articular fractures, which involve damage to the coffin joint, are far more serious. Any fracture involving a joint threatens the health of the joint and requires surgical reconstruction as soon as possible to prevent debilitating arthritis. The difficulty in treating these fractures lies in the foot’s structure; the bone is located inside the hoof, making it challenging to access. However, techniques exist that allow surgeons to place screws into the coffin bone through small resections of the hoof wall to stabilize fractures. This option is only viable when the fracture pattern and location are suitable.

Street Nail

A street nail surgery is used to treat deep penetrating injuries to the frog or sole of the foot, which can lead to infections in the coffin bone, navicular bone, and surrounding soft tissue structures. This procedure is necessary when a metal object, such as a nail or screw, penetrates and infects these vital structures. The surgical “window” allows for flushing of the synovial structures and removal of damaged or infected tissue.

Success of this procedure is greatly improved with the use of an arthroscopic camera, which can be placed in the navicular bursa or coffin joint, depending on the area affected by the puncture. The arthroscope allows for better visualization and more thorough flushing of debris and infection from these tight spaces. A special shoe called a hospital treatment plate is then applied to protect the foot while keeping it clean and accessible for further treatment.

Conclusion

As you can see, there is a common thread running through these hoof conditions: infection and the need for specialized farrier care. Successful treatment of these conditions requires close collaboration between the veterinary surgeon and farrier. While surgery on a horse’s foot is challenging and sometimes limited, many conditions can be successfully treated with the right surgical intervention and post-operative care.

By Garrett Metcalf, DVM

A foot abscess is a common occurrence in horses throughout the year, with wet weather often contributing to an increase in cases. These abscesses can cause significant pain, lameness, swelling, and overall misery, making it important to address them quickly and manage pain to keep the horse comfortable. There are various methods used to treat foot abscesses, and this article will outline techniques to evaluate and treat them as efficiently as possible.

A foot abscess is a localized or sometimes diffuse infection trapped between the sensitive and non-sensitive laminae within the hoof capsule. Abscesses may develop spontaneously due to everyday stress and environmental factors that allow bacteria to penetrate down to the sensitive tissues. Other causes include penetrating injuries to the sole from nails, sharp rocks, or even thorns. Poor hoof care and misdriven shoeing nails can also lead to abscess formation. Common sites include the white line, where the sole and hoof wall meet, and the bars of the heels.

The level of lameness caused by a foot abscess can vary, but it often results in visible discomfort at the walk and can even cause non-weight-bearing lameness. Swelling that begins at the foot and moves up the leg may occur, particularly if the abscess migrates and ruptures at the coronary band. These cases are often referred to as “gravel” abscesses, which are simply abscesses that find the path of least resistance and exit at the coronary band, creating a draining tract. In some cases, especially involving a hind foot, the horse’s movement may appear so abnormal that it mimics neurological issues, confusing owners and veterinarians.

Diagnosing a foot abscess begins with a lameness exam. Most affected horses will be visibly lame at the walk, though in some cases a trot may be necessary to detect the issue. Regional nerve blocks can help confirm that the pain is originating from the foot and not another part of the limb. Horses with abscesses often show an increased digital pulse and, occasionally, noticeable heat in the foot. The bounding pulse is due to inflammation and is most easily felt just above the hoof near the ankle. If the horse is shod, removing the shoe is often necessary for a thorough exam. Hoof testers are useful in identifying the most painful area, and horses with abscesses are typically reactive to pressure. Cleaning out the foot with a hoof knife is important for exposing any defects or tracts in the sole or frog. Often, a dark spot or line will lead to the source of the abscess.

There are multiple ways to treat an abscess, and opinions vary widely, but my preferred approach is to open the abscess as soon as possible. This provides nearly immediate relief for the horse and allows the infection to begin resolving. A sharp hoof knife or loop knife is a reliable tool to open the abscess and create drainage through the bottom of the foot. Allowing the abscess to drain from the sole reduces the risk of a gravel abscess and makes it easier to treat the area with topical poultices. After opening, it’s important to bandage the foot both to draw out remaining infection and to keep the area clean.

A large baby diaper makes a simple, effective bandage. It’s absorbent and fits the hoof well. Secure it with layers of Vetrap, duct tape, and Elastikon, or place the hoof in a medicine boot to keep it protected. Poultice choice is often based on personal experience and availability, but the goal is the same — to draw out infection and prevent contamination. Products like Magna Paste, an Epsom salt-based poultice, are effective, as is a homemade mix of sugar and Betadine. There are many other options, but whatever product is chosen should be safe and offer antimicrobial properties.

In some cases, an abscess may be difficult to locate or open. Soaking the foot in warm Epsom salt water can help soften the hoof and encourage the abscess to rupture or become easier to identify. Pain management is also helpful while waiting for the abscess to surface. If the abscess continues to recur or proves difficult to treat, radiographs can help evaluate the hoof’s internal structures. While most abscesses don’t show up on X-rays — since the fluid is the same density as the hoof — they may be visible if gas is present within the abscess. Radiographs are especially important in cases of puncture wounds, to ensure deeper structures like the coffin joint or navicular bursa aren’t involved. In cases of penetration, it’s best to leave the foreign object in place until X-rays are taken, which helps determine the extent of the injury and what structures may have been affected.

While preventing all foot abscesses isn’t always possible, good hoof care goes a long way. Regular trimming on a consistent schedule helps maintain healthy laminae and prevents stretching of the white line, which can allow bacteria to enter. Careful shoeing practices, including proper nail placement, can further reduce the risk of abscess development.

Foot abscesses are painful, frustrating, and often sudden — but with proper diagnosis, drainage, and aftercare, horses typically recover well and quickly return to soundness.

By Molly Bellefeuille, DVM, MS

Just like humans, horses may choke. Choke is a condition in which the esophagus is blocked, usually by food material. Horses with dental problems that do not grind their food properly and horses that do not take adequate time to chew are at risk (fractious horses, and horses that have to fight for their food). Dry foods may cause choke especially if the horse does not have free access to water. Pelleted/cubed feed and beet pulp are among the most common feeds that horses choke on. The risk of choke associated with dry feeds can be reduced by soaking the ration prior to feeding. Foreign objects such as wood, large chunks of apple, and blanket/lead rope pieces may also cause choke.

In horses signs of choke are excessive salivation, coughing, constant chewing, difficulty swallowing, disinterest in food, and extending the neck and head out. Choke is a medical emergency, as horses are often not able to resolve it on their own. Resolving it promptly is important because secondary to choke, aspiration pneumonia may develop if food material and saliva accumulate in the pharynx and spill over into the trachea and lungs.

Treatment of choke entails passing a nasogastric tube up the nose/down into the esophagus. If the tube will not pass into the stomach and hits resistance, it indicates a complete obstruction of the esophagus, while difficulty passing the tube may represent a stenosis or narrowing of the esophagus. If resistance is hit, warm water is pumped into the esophagus down the tube. Water helps soften the obstructing matter so it can pass on down the esophagus. Heavy sedation is used during this procedure to keep the horse’s head low and prevent aspiration of fluid into the trachea.  If the choke is not resolved with the passing of a nasogastric tube a video endoscope is passed down into the esophagus to assess the obstruction and small biopsy forceps can be used to pick apart/break up the obstruction. In severe cases the horse may have to be anesthetized and an orotracheal tube placed to prevent aspiration and allow for more vigorous flushing. If all of these techniques do not work, an incision can be made into the esophagus to remove the obstruction; however, if surgery is performed the horse is at risk of scarring down the esophagus/stenosis, which increases the chance that the horse may choke again.

After a choke is resolved, it is important to provide the horse with anti-inflammatory (banamine or bute) to help prevent any scarring. Depending upon the duration of the choke, horses are often placed on broad-spectrum antibiotics to help prevent the onset of aspiration pneumonia. Horses should also be kept on a soft feed to allow time for the esophagus to heal.

As stated before, chokes are an emergency and to give your horse the best chance at recovering it is important that a veterinarian see your horse if you suspect they are choking.

This article was originally published in the January 2016 issue of Oklahoma Farm & Ranch.