Gait Abnormalities and Disorders in Horses: Causes, Diagnosis & Treatment

Gait abnormalities in horses can lead to compromised performance, increased risk of injury, and in some cases, may necessitate early retirement from work. These disorders often present similarly to lameness, but do not necessarily involve pain.

While minor conformational faults are responsible for some abnormal equine movement patterns, changes in gait can also indicate a significant medical issue. Common causes of gait abnormalities include neurological diseases, muscular disorders, nerve damage, arthritis, and soft tissue injuries.

Early detection and appropriate treatment are key to managing these conditions effectively. The prognosis for a return to full function depends on the underlying cause.

Understanding standard gait movement patterns and the typical presentation of common gait disorders can help you determine when to call your veterinarian. Keep reading to learn how to recognize and manage common causes of gait abnormalities in horses.

Gait Abnormalities in Horses

Gait abnormalities refer to any deviation from the normal movement patterns typically exhibited by horses during walking, trotting, cantering, or galloping.

These abnormalities can include asymmetries and exaggerated movement patterns, uneven stride lengths, toe dragging, frequent stumbling, stiffness, altered head or neck positions, and other changes in stride quality.

These abnormalities not only affect the horse’s ability to move smoothly and efficiently, but also can impacting their overall health and well-being. Some gait abnormalities prevent horses from working or participating in competitive activities.

Irregular gaits can stem from various causes, including musculoskeletal issues, neurological impairments, hoof and foot problems, or congenital conditions. In the following sections, we discuss gait abnormalities caused by conformation faults, neuromuscular disorders and muscle and tendon issues.

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Conformation Faults

Your horse’s conformation can significantly influence his movement. Correct legs enable hooves to leave the ground symmetrically, travel straight, and land with minimal stress on the limb’s bones, joints, and soft tissues. ^[1]

In reality, many horses have less-than-perfect foot-flight patterns. While some conformational faults can increase the risk of lameness, most minor deviations don’t significantly affect your horse’s soundness and performance.

Forelimb Gait Abnormalities

Dishing is a common forelimb gait abnormality in horses characterized by an inward circular hoof motion during each stride. Exaggerated dishing is called “winging in.”

Paddling is an outward deviation of the lower foreleg during flexion while the horse is in motion. Winging is an exaggerated version of paddling noticeable in horses with elevated knee action.

Pigeon toes, or toed-in hoof conformation, is associated with dishing and paddling. Angled-in conformation originating from the knees or fetlock joints is more likely to produce movement deviations. ^[2]

Many Spanish breeds tend to paddle with their front legs in the trot. Good farrier care is essential for these horses, but sometimes corrective shoeing can do more harm than good if your horse is sound in his normal movement patterns.

Horses with forelimb dishing are also more likely to strike themselves and may benefit from wearing leg protection during exercise. ^[1]

Hindlimb Gait Abnormalities

Hindlimb gait abnormalities resulting from conformational faults include hooves twisting as they leave the ground and hocks swiveling during weight bearing. Exaggerated twisting can indicate pain in the hock. Subtle rotation is natural during hock flexion. This is to ensure the stifle can clear your horse’s belly as the hind leg advances. ^[3]

Unbalanced hooves can contribute to hock twisting in horses without existing conformational faults. Bowed-out hindlimbs can also indicate neurologic conditions or weakness.

Contact your veterinarian if your horse’s movement suddenly deviates from his usual patterns.

Neuromuscular Disorders

Horses with neuromuscular disorders often experience gait abnormalities. Neurological issues or injuries affect the communication between nerves and muscles, which is crucial for coordinated movement.

Gait evaluations are a standard part of neurological examinations for horses. These exams evaluate horses for gait abnormalities associated with ataxia, paresis, spasticity and hypermetria. ^[4]

• Ataxia: Poor muscle control causes a swaying, unstable gait with abnormal foot placement, which worsens when walking on a slope. Horses often pivot on affected limbs while backing or turning.
• Paresis: Partial paralysis and muscle weakness due to nerve damage or disease can cause feet dragging and stumbling. Signs are worsened when walking in a tight circle or up a slope.
• Spasticity: Rigid muscles cause stiff limb movement and reduced joint flexion. This symptom is worsened while walking up and down a slope with an elevated head.
• Hypermetria: Cerebellar dysfunction causes overstepping and excessive joint movement beyond the intended voluntary muscle response.

The presentation of neurological symptoms in horses varies depending on the neuromuscular disorder responsible for the gait abnormality.

Stringhalt

Stringhalt is a neuromuscular disorder of the horse’s hind limbs characterized by severe hyperflexion of the hock. It can affect one or both hindlimbs and occur in horses of any age or breed. ^[5]

Researchers have found a connection between stringhalt and nerve damage affecting the muscle spindles of the lateral digital extensor tendon. Clinical signs can arise suddenly, ranging from mild hyperflexion to violently hitting the belly with the affected hindleg. ^[5]

Stringhalt in horses can present as either acquired or idiopathic:

• Acquired cases often result from plant toxicity (usually fitweed a.k.a. false dandelion) and cause temporary clinical signs. Although known as Australian stringhalt, this form occurs worldwide. Horses with this form may also experience laryngeal paralysis. ^[6]
• Idiopathic cases are typically caused by trauma or injury. Clinical signs can improve after healing. Strenuous exercise, cold weather, excitement, and anxiety can worsen symptoms. ^[6]

Some horses recover spontaneously. Treatment for chronic stringhalt may include medications or surgical resection of the affected muscle and tendon, but success is variable.

Shivers

Shivers is a progressive neuromuscular disorder associated with gait abnormalities while backing up. Affected horses have muscle tremors in their pelvic region, producing jerky movements in the hindlegs. ^[6]

Elevating the hindleg off the ground can trigger a spastic state, which is exacerbated by excitement or stress. This disease is commonly found in draft horses but can affect a variety of horse breeds, including Warmbloods, Quarter Horses, and Thoroughbreds. ^[7]

Early signs of shivers often include the horse snatching a limb up when going to pick their feet. Farrier work is often challenging for these horses.

Shivers is caused by degenerative lesions on nerve cells deep in the brain, and there is no cure for the disease. ^[8] In severe cases, it can progress to generalized muscle atrophy. Research suggests exercise and regular turnout can help reduce episodes in affected horses. ^[7]

Sweeney Shoulder

Sweeney shoulder, also known as shoulder slip, is a gait abnormality characterized by a loss of collateral support for the shoulder. Clinical signs of the disease involve atrophy of muscle in the shoulder caused by damage to the suprascapular nerve. ^[9] Muscle atrophy makes the bony spine of the scapula prominent in these horses. ^[9]

Chronic cases of Sweeney shoulder commonly occurred in working horses that have pulled heavy loads in ill-fitting harness collars. Nowadays, acute cases of this condition are more common than chronic cases.

Acute Sweeney shoulder usually results from trauma to the shoulder, such as from a kick or an impact with a fence. The shoulder region becomes unstable, and the shoulder joint partially dislocates when the horse goes to bear weight on their leg.

Horses can recover shoulder stability over time, but it typically takes six to eight months for the nerve to heal and regrow. Recovery time can be reduced by acupuncture and working the horse with a 2 lb (1 kg) weight around the fetlock. Atrophy of the muscle is usually permanent. ^[9]

Dropped Elbow

Dropped elbow is a condition in horses where there is an apparent sagging of the elbow joint due to an inability to properly extend the forelimb. This condition is often associated with dysfunction of the radial nerve, which controls muscles that extend the elbow, wrist, and digits. ^[10]

Dropped elbow may be caused by trauma to the elbow, such as a fracture, or compression of the radial nerve due to prolonged lateral recumbency (lying down on the side). ^[10]

This can lead to radial nerve paresis, a neurological condition in horses involving weakness or partial paralysis (paresis) of the muscles innervated by the radial nerve. Horses with complete radial paralysis can’t extend their forelimb or bear weight on the affected limb. ^[10]

Horses that show improvement over the first few days of rest have a good prognosis for recovery. Splinting the leg in extension can provide limited limb use during the rehabilitation period.

Tetanus

Tetanus is a serious bacterial infection caused by the Clostridium tetani bacteria. These bacteria are abundant in soil and produce a neurotoxin that affects motor neurons, leading to uncontrolled muscle contractions. ^[11]

Horses affected by tetanus experience a progressively stiff gait and muscle spasms. Affected horses often have a characteristic sawhorse stance and may develop lockjaw, an inability to open the mouth. Extreme muscle rigidity makes it difficult for horses to move.

Prompt and aggressive treatment is crucial for affected horses. Treatment usually involves tetanus antitoxin, antibiotics, and supportive care to manage symptoms and prevent complications. The prognosis is poor for horses with severe clinical signs. ^[11]

While this disease has a high mortality rate, effective tetanus vaccines are available to protect equines from developing this infection. ^[11]

Musculotendinous Disorders

Disorders affecting the muscles and tendons can also result in gait abnormalities due to a loss of mechanical function. Some of these conditions cause pain and lead to lameness, while others result in more subtle gait abnormalities.

Rhabdomyolysis

Rhabdomyolysis is a muscle condition characterized by the rapid breakdown of skeletal muscle tissue, leading to muscle pain, gait stiffness, and a reluctance to move. Several diseases can contribute to rhabdomyolysis, leading to similar clinical signs and gait abnormalities. ^[12]

Exertional rhabdomyolysis, or tying-up, is one of the most common causes of acute gait abnormalities in horses. During a tying-up episode, horses may only take short, shuffling steps. Proper exercise routines can help prevent tying-up in horses with sporadic episodes.

Some horses are genetically predisposed to tying up due to muscle conditions such as Polysaccharide storage myopathy (PSSM). These horses need a low-starch diet and regular exercise to reduce their risks of tying up. ^[12]

Other causes of repeated bouts of tying-up include RER (recurrent exertional rhabdomyolysis), malignant hyperthermia and myofibrillar myopathy.

Fibrotic Myopathy

Fibrotic myopathy is a mechanical lameness caused by the formation of abnormal scar tissue, which impairs normal muscle elasticity and function. This condition most commonly affects the hamstring muscles of the upper hind limbs.

Trauma, repetitive strain, hyperextension, infection, and repeated intramuscular (IM) injections can contribute to scar tissue formation. The gait of affected horses is marked by the leg abruptly halting its forward motion mid-air and then slapping down onto the ground. ^[13]

Horses with chronic cases of fibrotic myopathy often have hardened areas of muscle. Acute clinical signs of this disorder can include warm, sore muscles, but not all affected horses experience pain due to this condition.

Rest, icing, stretching, shockwave, and other therapies can help treat this disorder ^[13]

Upward Patella Fixation

Upward fixation of the patella in horses can cause the hindleg to become locked in extension. This disorder is typically seen in young horses.

In horses with this disorder, the medial patellar ligament gets stuck on the femur during limb extension. Some horses may experience complete fixation, which requires them to drag their toe behind them to move. ^[14]

A jerking motion can occur when the ligament releases. Owners sometimes confuse this movement for stringhalt. Mild cases can result in a jerky gait due to delayed ligament release during exercise.

Upward patella fixation may occur after prolonged stall rest or in young horses with poor quadricep condition. Exercise programs that strengthen the surrounding musculature can improve clinical signs, but some horses may need surgery to fix persistent locking. ^[14]

Peroneus Tertius Rupture

The peroneus (fibularis) tertius is part of the reciprocal apparatus of the horse’s hindlimb that enables concurrent flexion and extension of the stifle and hock. Hyperextension of the hindlimb can result in a rupture of this structure and abnormal joint movement. ^[15]

This condition allows the hock to extend while the stifle is flexed. Affected horses have gait abnormalities characterized by limited hock flexion while the leg moves forward. The limb appears to hang during protraction.

Conservative treatment with stall rest and careful rehabilitation can help horses fully recover. ^[15]

Gastrocnemius Rupture

The gastrocnemius muscle flexes the stifle joint and extends the hock. Ruptures of this structure cause a significant loss of support to the limb. The hock folds when horses attempt to bear weight on a limb with a gastrocnemius rupture.

Partial injury to the gastrocnemius causes a gait abnormality characterized by slight hock hyperextension and medial toe rotation.

Research suggests this gait helps affected horses relieve pain and is not a result of mechanical dysfunction. Similar gait abnormalities occur in horses with spinal ataxia and generalized weakness. ^[16]

Newborn foals can develop a gastrocnemius rupture during assisted deliveries and dystocia (difficult birth) if the stifle is forced into overextension while the hock is flexed. Adult horses can develop a tear from athletic injuries associated with strenuous stopping.

With extended rest, the prognosis is good for horses with partial tears that don’t disrupt the reciprocal apparatus. ^[16]

Summary

• Gait abnormalities can result from conformational faults, neurological issues, or mechanical loss of function.
• Some gait abnormalities may appear similar to lameness but do not respond to nerve blocks, indicating an absence of pain.
• Neurological exams and gait evaluations can help owners and veterinarians determine the cause of any changes in locomotion.
• While some gait abnormalities don’t significantly impact performance and soundness, others can indicate a serious underlying medical issue.
• Consult your veterinarian if you notice any concerning changes in your horse’s gait.