Navicular Disease in Horses: Causes, Symptoms, and What You Can Actually Do

What Navicular Disease Actually Is

Your vet says "navicular" and your stomach drops. It is one of those words that echoes around barns like a death sentence, passed between horse people in hushed tones alongside stories about somebody's mare who was never sound again. But here is the thing: navicular disease is not one single condition. It is a syndrome, a collection of problems in a very specific region of the horse's foot, and the spectrum runs from mild and manageable all the way to career-ending.

The term "navicular syndrome" has largely replaced "navicular disease" in veterinary literature, because researchers realized decades ago that blaming everything on the navicular bone itself was too simplistic. Horses showing heel pain and caudal foot lameness might have bone degeneration, soft tissue damage, bursal inflammation, or some messy combination of all three. The navicular bone takes the blame, but it is rarely acting alone.

What most owners want to know is straightforward: Can my horse still be ridden? Will this get worse? What are my options? Those are fair questions, and the answers depend entirely on which structures are damaged, how badly, and what you are willing to do about it. No two navicular horses are identical, and blanket predictions help nobody.

The Anatomy You Need to Understand

Before anything else makes sense, you need a mental picture of what is happening inside the hoof. The navicular bone (also called the distal sesamoid bone) is a small, boat-shaped bone that sits behind the coffin joint, nestled between the short pastern bone above and the coffin bone below. It is not weight-bearing in the traditional sense. Its job is to act as a fulcrum, a pivot point for the deep digital flexor tendon (DDFT) as that tendon wraps around and attaches to the bottom of the coffin bone.

Think of the navicular bone like a pulley in a mechanical system. The DDFT runs down the back of the leg, passes over the navicular bone, and inserts on the solar surface of the coffin bone. Between the tendon and the bone sits the navicular bursa, a fluid-filled sac that reduces friction. This whole arrangement allows the coffin joint to flex smoothly when the horse moves.

Surrounding all of this are ligaments. The impar ligament connects the navicular bone to the coffin bone. The suspensory ligaments of the navicular bone (collateral sesamoidean ligaments) hold it in position from above. When any of these structures become damaged or inflamed, you get pain. And because the foot is encased in a rigid hoof capsule, swelling has nowhere to go, which makes everything worse.

Explore the navicular bone and surrounding structures in our interactive 3D horse model →

The blood supply to this region is limited, which is part of the problem. The navicular bone receives blood through small arteries that enter at its borders. Anything that compromises blood flow (concussion, compression, poor hoof balance) can lead to bone deterioration over time. Cartilage on the flexor surface erodes, cysts form within the bone, and the DDFT begins to fray where it contacts roughened bone. It is a slow, grinding process in most cases.

Why Horses Develop Navicular Problems

Nobody has pinned down a single cause, and anyone who tells you otherwise is oversimplifying. Navicular syndrome appears to develop from a combination of factors stacking up over time.

Conformation plays a significant role. Horses with small feet relative to body size, upright pasterns, or long toes with underrun heels tend to overload the navicular region. The mechanics are straightforward: if the hoof is shaped in a way that concentrates force on the back of the foot, the navicular bone and DDFT absorb more impact than they were designed to handle. Quarter Horses, Thoroughbreds, and Warmbloods show up disproportionately in navicular statistics, partly due to conformation tendencies and partly due to the work asked of them.

Improper or infrequent trimming compounds the problem. A horse that goes eight weeks between farrier visits develops long toes and crushed heels. That shifts the breakover point forward, increasing leverage on the DDFT every single stride. Multiply that by thousands of steps per day and you have a recipe for chronic damage. Many navicular cases could have been delayed or prevented entirely with six-week trim cycles and a farrier who understands hoof balance.

Workload and footing matter. Horses working on hard surfaces take more concussion through the foot. Repetitive jumping, especially on firm ground, hammers the navicular region. Horses in heavy training that never get turnout on soft footing accumulate micro-damage faster than the body can repair it.

Age is a factor, though not in the way most people assume. Navicular syndrome typically shows up between ages 7 and 14. Young horses rarely present with it because they have not accumulated enough wear. Older horses sometimes seem to "outgrow" lameness as they slow down naturally and the demands on the foot decrease. The peak years coincide with peak athletic careers, which is not a coincidence.

Genetics almost certainly contribute. Some bloodlines produce navicular horses generation after generation, regardless of management. Breeding for speed and agility without considering foot structure has produced populations of horses with beautiful movement and terrible feet. That tradeoff catches up eventually.

Recognizing the Signs

Navicular syndrome is sneaky. It does not announce itself with dramatic swelling or an obvious injury event. Instead, it creeps in. The horse feels slightly off one day, fine the next, then off again a week later. Owners often describe it as the horse "not being himself" rather than outright lame.

The classic presentation involves intermittent forelimb lameness, frequently shifting between legs. One day the left front looks short, then it seems fine, then the right front takes a funny step. This shifting pattern happens because both front feet are often affected. The horse loads whichever foot hurts less, so lameness appears to jump sides.

Pointing is another hallmark. At rest, the horse stands with one front foot slightly forward, heel off the ground, taking weight off the back of the foot. Watch your horse standing in the crossties or at the hitching post. A navicular horse often alternates which foot it points, resting one then the other.

Other signs to watch for:

• Shortened stride, especially at the trot on hard ground
• Reluctance to go downhill (this loads the heels)
• Stumbling or tripping more than usual
• Landing toe-first instead of heel-first at the walk (visible on slow-motion video)
• Sensitivity to hoof testers applied over the central third of the frog
• Gradual performance decline that does not respond to rest

One frustrating aspect of navicular syndrome is that the horse may look perfectly sound on soft footing and fall apart on pavement or packed arena footing. If your vet asks you to trot the horse on asphalt, that is why. Hard surfaces amplify heel pain and make subtle lameness visible.

Getting a Diagnosis That Means Something

Here is where things get complicated. X-rays alone are not enough, and any vet worth their salt will tell you that. Radiographic changes in the navicular bone (enlarged synovial fossae, lollipop lesions, bone remodeling) are common in horses that are completely sound. Conversely, horses with devastating navicular pain sometimes have clean X-rays because the damage is in soft tissues that do not show on radiographs.

Diagnostic nerve blocks are the foundation of a navicular workup. The vet injects local anesthetic around specific nerves to systematically numb parts of the foot. If the horse improves after a palmar digital nerve block (which numbs the back of the foot, including the navicular region), that confirms the pain is coming from somewhere in the caudal foot. Additional blocks can narrow the location further.

MRI is the gold standard for navicular diagnosis, and it is not even close. Standing MRI units (the horse stays awake, foot placed in a magnet) have made this accessible at many equine hospitals. MRI shows bone, cartilage, tendons, ligaments, and the bursa in exquisite detail. It can reveal DDFT lesions, navicular bone edema, impar ligament tears, and bursal inflammation that no other imaging can detect.

The catch? MRI costs between $1,500 and $3,000 depending on your location and whether the horse needs general anesthesia. That is real money. But if you are making treatment decisions that could involve years of corrective shoeing, expensive medications, or surgery, knowing exactly what is damaged saves money and heartache in the long run. Treating the wrong structure is worse than not treating at all.

Ultrasound can evaluate some soft tissue structures, particularly the DDFT where it passes through the pastern. It is less expensive than MRI but cannot see inside the hoof capsule well. Nuclear scintigraphy (bone scan) highlights areas of active bone remodeling and can confirm navicular involvement, but it does not show soft tissue detail. Each imaging tool has a role, but MRI gives you the complete picture.

Treatment Options That Exist Right Now

Treatment for navicular syndrome is management, not cure. That sentence needs to sit with you for a moment because it changes expectations. The goal is to reduce pain, slow progression, and keep the horse comfortable at whatever level of work is realistic. Some horses return to full athletic careers. Others become pasture sound. A few do not improve meaningfully despite everything.

NSAIDs (phenylbutazone, firocoxib) are the first line of defense. Bute takes the edge off inflammation and pain, making the horse more comfortable during work and allowing more normal movement patterns. Firocoxib (Equioxx) is gentler on the gut for long-term use. The risk with NSAIDs is masking pain to the point where the horse does more damage because it does not feel the warning signals. Work with your vet to find the lowest effective dose.

Isoxsuprine and other vasodilators have been used for decades on the theory that improving blood flow to the navicular bone slows degeneration. The evidence is mixed. Some horses seem to improve, others show no change. It is inexpensive and low-risk, so many vets still prescribe it as part of a broader management plan.

Bisphosphonates (tiludronate, sold as Tildren; clodronate, sold as Osphos) are relatively newer options. These drugs inhibit bone resorption, which may slow the bone remodeling process in the navicular bone. Given as IV infusion or intramuscular injection, they take several weeks to reach full effect. Some horses show marked improvement. Others do not respond. The cost is significant, usually $800 to $1,200 per treatment, and the effects may last six months to a year before retreatment is needed.

Navicular bursa injections deliver corticosteroids directly into the navicular bursa, targeting inflammation right at the source. This is a skilled procedure, often done under radiographic guidance, and carries a small risk of infection. When it works, the relief can be dramatic and last months. It buys time and comfort while other management strategies take hold.

For more on the structures involved and how they relate, check our equine anatomy encyclopedia.

Corrective Shoeing and Trimming

If there is one intervention that matters more than any other for navicular horses, it is what happens on the bottom of their feet every five to six weeks. Corrective shoeing is not optional. It is the foundation of every successful navicular management plan.

The principles are consistent even though the execution varies:

• Ease breakover. A rolled toe or rocker toe shoe reduces the leverage the DDFT exerts on the navicular bone at every step. Square-toed shoes achieve the same thing.
• Support the heels. Egg bar shoes, straight bar shoes, or shoes with extended heel coverage spread load across a larger area and support the heels.
• Protect the sole. Pads (leather, plastic, or pour-in) shield the sole from direct ground contact and reduce concussion.
• Raise the heels (maybe). Degree pads or wedge shoes tilt the foot slightly, reducing tension on the DDFT. This works short-term but long-term heel elevation can actually crush the heels further. The trend in progressive farriery is moving away from chronic wedging.

Your farrier and vet need to work as a team. The best shoeing plan accounts for the specific damage shown on MRI, the horse's current hoof shape, its workload, and its footing. A farrier who has never looked at an MRI report is flying blind. A vet who does not consult the farrier is missing half the picture.

Some navicular horses do well barefoot with boots for riding, especially if the underlying problem is mild and the horse has decent foot structure. Transitioning to barefoot from shoes requires patience and a knowledgeable trimmer. It is not the right choice for every horse, but for some, removing the shoe allows the hoof to function more naturally and improve blood flow through the digital cushion.

When Surgery Comes Up

Surgery is not the first conversation, and it should not be. But for horses that fail conservative management, two surgical options exist.

Navicular cyst surgery (navicular bursoscopy with cyst debridement) addresses cystic lesions within the navicular bone. Under general anesthesia, a surgeon uses an arthroscope inserted into the navicular bursa to access and debride the cyst. Success rates are moderate, with published studies showing around 50 to 60 percent of horses returning to some level of work. The procedure works best when the cyst is the primary source of pain and other structures are relatively intact. If the DDFT is shredded and the bone is riddled with lesions, removing one cyst is not going to fix the bigger problem.

Palmar digital neurectomy (nerving) is the procedure that generates the most debate. The surgeon cuts the palmar digital nerves, permanently removing sensation from the back of the foot. The horse can no longer feel navicular pain. It sounds like a silver bullet, and in some cases the results are remarkable: years of soundness, return to full work, a happy horse.

The risks are real, though. Without sensation, the horse cannot feel injuries to the back of the foot. A puncture wound, abscess, or worsening bone damage goes undetected until it becomes severe. Neuromas (painful nerve regrowth) can develop at the cut site, creating new lameness worse than the original problem. Nerves sometimes regenerate partially, and sensation returns unevenly. Regular monitoring with hoof testers, thermography, and imaging becomes essential after neurectomy.

Neurectomy is typically a last resort for horses that are otherwise going to be euthanized due to unmanageable pain. When the alternative is a bullet, cutting the nerves makes a lot of sense. When the alternative is conservative management that has not been fully optimized, maybe slow down and try harder first.

The Honest Prognosis Talk

Here is what nobody wants to hear: prognosis depends almost entirely on what the MRI shows. A horse with mild navicular bone remodeling and an intact DDFT has a good chance of returning to work with proper shoeing and management. A horse with a torn DDFT, extensive bone lysis, and chronic bursal effusion has a guarded prognosis at best.

Studies tracking navicular horses over time show that roughly 60 to 70 percent can return to some level of athletic work with appropriate management. That number drops significantly for upper-level athletes. The horse that was jumping 1.30m courses might come back as a flatwork horse or low-level jumper. Accepting a change in career is sometimes the most compassionate decision.

Horses that respond well to initial treatment (corrective shoeing plus NSAIDs) within the first two to three months tend to have better long-term outcomes. Horses that do not improve despite aggressive management are telling you something about the severity of the underlying damage.

Living With a Navicular Horse

Managing a navicular horse is a marathon, not a sprint. It requires attention to detail, a consistent farrier schedule, and a willingness to adjust the plan as things change.

Turnout on soft footing helps. Movement promotes blood flow to the foot and prevents stiffness. A horse standing in a stall 23 hours a day is worse off than one moving around a grass paddock, even if the lameness looks more obvious when the horse moves. Controlled exercise on good footing (not deep sand, not rock-hard ground) keeps the horse fit without hammering the feet.

Footing matters enormously. If your arena is hard-packed clay, your navicular horse will struggle. If it is well-maintained fiber or sand-rubber mix, you have a better chance. Trail riding on varied terrain can actually be beneficial because it changes the loading pattern on the foot, rather than repeating the same forces on the same structures lap after lap in an arena.

Monitor your horse's feet obsessively. Feel for heat daily. Watch for changes in digital pulse. Video the horse trotting on hard ground once a month so you can detect subtle changes before they become obvious lameness. Keep a log. Your future self (and your vet) will thank you.

Weight management is underrated. Every extra pound the horse carries translates to more force through the feet. An overweight navicular horse is working against itself. Keep body condition at a 4.5 to 5 out of 9, lean enough to feel ribs easily.

Work with your vet to develop a treatment calendar: when to reassess, when to reshoe, when to consider imaging, when to adjust medications. Navicular syndrome responds best to proactive management, not crisis response.

Study the structures involved and their relationships in detail in our anatomy courses. Understanding what is happening inside the hoof changes how you think about every management decision.