Navicular Disease in Horses: Modern Management Approaches

Reviewed by Dr. Khurrum Shahzad Khosa, DVM

Navicular disease is one of the most common causes of forelimb lameness in horses and has been recognised by equine practitioners for centuries. Despite this long history of clinical awareness, our understanding of the condition has evolved substantially in recent decades. What was once considered a simple bone disease is now recognised as a syndrome involving multiple structures within the caudal (back) part of the foot — the navicular bone, the deep digital flexor tendon, the navicular bursa, and several supporting ligaments. The term "navicular syndrome" or "caudal heel pain syndrome" has largely replaced "navicular disease" in veterinary literature to reflect this broader understanding, though the older term remains in common use among horse owners. Understanding what navicular syndrome actually is — and what modern management can realistically achieve — is important for any owner navigating this diagnosis.

Anatomy of the Caudal Foot

To understand navicular syndrome, it is helpful to understand the structures involved. The navicular bone (also called the distal sesamoid bone) is a small, boat-shaped bone located at the back of the foot, between the second and third phalanges (short and coffin bones). Its primary function is to act as a pulley for the deep digital flexor tendon (DDFT), which runs down the back of the lower leg, wraps around the navicular bone, and attaches to the underside of the coffin bone. The navicular bone thus bears enormous compressive and tensile forces with every stride.

The navicular bursa is a fluid-filled sac positioned between the flexor surface of the navicular bone and the DDFT. It reduces friction between these structures during movement. The impar ligament connects the navicular bone to the coffin bone, while the collateral sesamoidean ligaments stabilise the navicular bone within the foot. The digital cushion — a pad of fibrocartilaginous and fatty tissue in the heel — plays an important role in absorbing impact forces in this region.

Navicular syndrome can involve pathology in any or all of these structures: degeneration or cyst formation within the navicular bone, erosion or tearing of the DDFT at its contact surface with the navicular bone, thickening of the navicular bursa, and deterioration of the supporting ligaments. This is why modern imaging — particularly MRI — has so dramatically improved diagnosis, as it can visualise all these structures simultaneously.

Causes and Risk Factors

Navicular syndrome is considered a degenerative condition, with chronic repetitive mechanical stress the primary driver. Horses in work subject their caudal feet to enormous, repetitive loading forces — the navicular bone and associated structures absorb impact with every footfall over thousands of training and competition miles. Over time, this cumulative loading leads to the degenerative changes characteristic of the syndrome.

Conformation significantly influences risk. Horses with upright pasterns transmit more concussive force directly through the foot rather than dissipating it through the pastern angle. A long toe, low heel hoof configuration — often the result of inadequate farriery — places greater tension on the DDFT and increases the force on the navicular bone. Small feet relative to body mass similarly concentrate forces on the navicular structures. Contracted heels compromise the digital cushion and reduce the foot's ability to absorb impact effectively.

Breed predisposition is well-recognised. Thoroughbreds, Quarter Horses, and Warmblood types — horses used in high-demand athletic work with relatively small, upright feet — are most commonly affected. The condition predominantly affects the forelimbs, and bilateral involvement is the rule rather than the exception, as both forefeet are exposed to similar biomechanical stresses.

Clinical Signs

The onset of navicular syndrome is typically insidious — the lameness develops gradually over months to years rather than appearing suddenly. Early signs can be subtle and easily attributed to other causes or dismissed as the horse having a stiff day. Recognising the pattern is important for early intervention, which consistently produces better long-term outcomes than late diagnosis.

Intermittent, shifting forelimb lameness that appears worse on hard ground and at the beginning of exercise (before the horse "warms out of it") is one of the most characteristic early presentations. The horse may appear stiff and reluctant to move freely, particularly when ridden on a circle or on a firm surface.

Pointing — resting one foreleg with the toe placed in front of the contralateral foot to relieve pressure on the caudal heel — is a classic sign and is often noticed at rest in the stable or field. When both feet are affected, the horse may alternate which foot it points or may stand with both forefeet advanced.

Shortened anterior stride — a choppy, shuffling gait with reduced extension of the forelimbs — is typical. The horse appears to take short, careful steps and lacks the free forward movement expected. Stumbling, tripping, and reluctance to work on circles or in lateral work are common owner complaints. In more advanced cases, the horse may show consistent, measurable forelimb lameness that does not improve with warming up.

Hoof conformation may deteriorate over time — progressive heel contraction can occur as the horse lands toe-first to avoid caudal heel pain, reducing the expansion of the heels that is necessary for normal hoof growth and digital cushion development.

Diagnosis

Diagnosis of navicular syndrome begins with a comprehensive lameness evaluation. Your veterinarian will observe the horse moving at walk and trot on both hard and soft ground, assess response to flexion tests, and examine the hooves for conformation, balance, and the presence of heel contraction. The horse is typically worse on circles, particularly on the affected limb on the inside of the circle, and worse on firm surfaces.

Palmar digital nerve blocks are the key diagnostic tool. Injecting local anaesthetic to desensitise the caudal third of the foot — the region containing the navicular structures — typically produces a significant improvement in lameness if the source of pain is in this region. This is essential for confirming caudal heel pain as the source of lameness before proceeding to imaging.

Radiography provides information about the navicular bone itself — changes in the shape of the distal border, cyst-like lucencies within the bone, new bone formation, and enthesophyte development at ligament attachment sites are all radiographic indicators of navicular pathology. However, radiographic findings are poorly correlated with clinical severity, and horses with significant radiographic changes may have mild lameness while others with minimal changes are severely affected.

MRI is now considered the gold standard for navicular syndrome diagnosis and is essential when surgical options are being considered or when soft tissue pathology (DDFT lesions, bursal disease, ligament damage) is suspected. It provides clear visualisation of all structures within the foot simultaneously and guides targeted treatment decisions more effectively than any other imaging modality. For more information on equine lameness and foot conditions, explore our full collection of horse health guides.

Treatment and Management

Corrective shoeing is the foundation of navicular syndrome management and can produce dramatic improvements in comfort. The goals are to raise the heels to reduce DDFT tension, broaden heel support, and ease the breakover point. Wide-webbed egg-bar shoes, wedge pads, and rocker-toed shoes are commonly used, often in combination. A skilled farrier working in close collaboration with your veterinarian is essential — the specific approach must be tailored to the individual horse's foot conformation and the structures identified on imaging.

NSAIDs — phenylbutazone or meloxicam — provide effective short-term pain relief and are useful for acute painful periods, but are not appropriate as long-term sole management without attention to underlying structural causes. Bisphosphonate therapy (tiludronate or clodronate) is an increasingly used medical treatment targeting the abnormal bone remodelling process within the navicular bone, with evidence for meaningful improvement in a subset of horses. Navicular bursa injections with corticosteroids and hyaluronic acid can provide significant pain relief in horses with bursal disease.

Palmar digital neurectomy — surgical severing of the nerves to eliminate caudal foot pain — is reserved for horses that have failed conservative management. The procedure can restore comfort and working ability for several years but carries specific risks and management obligations that owners must fully understand before proceeding.

Frequently Asked Questions

Is navicular disease curable?

Navicular disease is generally considered a manageable, progressive condition rather than a curable one. Degenerative changes cannot be reversed, but many horses are kept comfortable and in work for years with appropriate corrective shoeing, exercise management, and medical treatment. The prognosis depends on severity at diagnosis, conformation, workload, and consistency of management.

What breeds are most commonly affected by navicular disease?

Thoroughbreds, Quarter Horses, and Warmbloods in athletic work are most commonly affected. Conformation risk factors include upright pasterns, long-toe/low-heel hoof configuration, small feet relative to body mass, and contracted heels. The condition predominantly affects the forelimbs and is often bilateral.

How is navicular disease diagnosed?

Diagnosis involves a lameness examination, palmar digital nerve blocks to localise pain to the caudal foot, radiography to assess the navicular bone, and ideally MRI to evaluate all soft tissue structures. MRI is considered the gold standard as it detects DDFT lesions, bursal disease, and ligament pathology that radiographs cannot show.

What is the role of corrective shoeing in navicular disease?

Corrective shoeing is the cornerstone of management. It aims to raise the heels to reduce DDFT tension, broaden heel support, and optimise breakover mechanics. Egg-bar shoes, wedge pads, and rocker-toed shoes are commonly used. A skilled farrier working with your vet and tailoring the approach to the individual horse is essential.

What is a palmar digital neurectomy and when is it used?

Neurectomy (nerving) is a surgical procedure that severs the palmar digital nerves to eliminate caudal foot pain. It is a last-resort option for horses where conservative management has failed. Benefits typically last several years, but the procedure requires meticulous daily hoof care of the desensitised foot and carries a risk of DDFT rupture in horses with significant tendon pathology.

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Disclaimer: This article is for educational purposes only and does not constitute veterinary advice. Always consult a licensed equine veterinarian for diagnosis and treatment.