Tendon Injuries

Tendon injuries are among the most common orthopedic problems affecting horses, causing significant lameness and potentially ending athletic careers if not managed properly. The flexor tendons in the lower legs are particularly vulnerable to injury because they bear tremendous weight and stress during movement, jumping, and work. Whether your horse is a performance athlete or a backyard companion, understanding how tendon injuries develop, recognizing early warning signs, and knowing the steps to take when injury occurs can make the difference between a successful recovery and chronic lameness.

Tendon injuries range from minor inflammation that responds well to conservative treatment to severe tears that require months or years of rehabilitation. Recovery depends on the location and severity of the injury, your horse’s age, and how quickly you respond to the first signs of trouble. This guide provides horse owners with practical information about tendon injuries, their treatment options, and realistic recovery expectations. Always consult an equine veterinarian for diagnosis and treatment planning, as this article is not a substitute for professional veterinary care.

Anatomy and Function of Horse Tendons

Tendons are tough, fibrous tissues that connect muscle to bone and enable movement by transmitting the force generated by muscle contraction to the skeletal system. In the horse’s lower leg, several tendons work together to support the weight and facilitate motion. The two most commonly injured tendons are the superficial digital flexor tendon (SDFT) and the deep digital flexor tendon (DDFT), both located on the back of the cannon bone.

These flexor tendons run from the forearm down the back of the leg and attach to the bones of the foot, allowing the horse to bend the fetlock, pastern, and coffin joints. The suspensory ligament, technically a ligament rather than a tendon but often grouped with tendon injuries, runs down the back and sides of the cannon bone and helps support the fetlock joint. Because these structures bear approximately 1.5 times the horse’s body weight during each stride, they are under constant stress and particularly vulnerable to damage from overwork, poor footing, training mistakes, and age-related changes.

Common Causes of Tendon Injuries

Acute Trauma

Sudden, severe injuries can damage tendons instantly. These include stepping in a hole, slipping on ice or muddy footing, sudden stops or turns at speed, falls, or being kicked. Acute injuries typically cause immediate lameness and swelling that is noticeable within minutes to hours.

Overuse and Fatigue

Repetitive stress from excessive work, intense training, or returning to work too quickly after a layoff can cause tendon fibers to break down gradually. This is the most common cause of tendon injury in performance horses. Horses asked to work beyond their current fitness level develop cumulative micro-damage in tendon fibers that eventually results in visible injury.

Poor Conformation and Shoeing

Horses with congenital leg deviations or unbalanced feet are predisposed to tendon stress. Improper shoeing that affects how weight is distributed across the foot and leg can increase load on tendons. Long hooves, contracted heels, and shoes that are too long or heavy place additional strain on already-stressed structures.

Footing and Terrain

Hard, compacted ground increases concussive forces traveling up the leg. Conversely, working on deep footing like sand requires more muscle effort and energy and can fatigue tendons more rapidly. Uneven footing increases the risk of missteps and sudden loading of tendons.

Age and Prior Injury

Tendons become less elastic and more prone to injury as horses age. Horses that have had previous tendon injuries have a significantly higher risk of re-injury in the same leg or the opposite leg, since they often compensate by putting extra load on their uninjured limbs during recovery.

Signs and Symptoms of Tendon Injury

Acute Injury Signs

Immediately after acute tendon injury, you may observe:

• Sudden, severe lameness that may improve slightly with rest over the first 24-48 hours
• Significant swelling in the lower leg that develops within hours
• Heat in the injured leg
• Pain or flinching when the leg is touched
• Reluctance to bear weight on the affected leg
• Visible fluid accumulation around the tendon area

Chronic or Progressive Injury Signs

When tendon damage develops gradually, the signs may be subtle at first:

• Intermittent lameness that worsens with hard work or after rest
• Stiffness that improves as the horse warms up
• Gradually developing swelling on the back of the leg
• Thickened or enlarged tendon that you can feel by running your hand down the leg
• Heat in the tendon area
• Changes in gait or stride length
• Reluctance to work or resistance to certain movements

Any sudden change in lameness or persistent swelling warrants an immediate veterinary examination. Do not wait or assume the injury will resolve on its own.

Diagnosis of Tendon Injuries

Your veterinarian will perform a thorough lameness evaluation, palpating the affected leg carefully to identify areas of heat, swelling, and pain response. However, clinical examination alone cannot determine the exact location and extent of tendon damage. Most tendon injuries require advanced imaging for accurate diagnosis.

Ultrasound

Ultrasound is the primary tool for diagnosing tendon injuries. It produces detailed images of soft tissues and allows your veterinarian to visualize the tendon fibers, identify areas of damage, and assess the extent of injury. Ultrasound findings are typically graded on a scale that helps determine treatment options and recovery prognosis. Your veterinarian may recommend ultrasound examination at the initial injury and again at intervals during recovery to monitor healing.

Radiographs (X-rays)

X-rays are used to rule out bone fractures or other bony abnormalities that might be causing lameness. They also help evaluate conformation and shoeing-related issues contributing to tendon stress.

MRI

Magnetic resonance imaging provides the most detailed images of soft tissue damage and is sometimes recommended for high-value horses or when the extent of injury is unclear. MRI is not always necessary for routine tendon injury management but can be valuable for determining prognosis and planning rehabilitation.

Treatment Options for Tendon Injuries

Rest and Controlled Activity

Complete stall rest for the first 2-4 weeks is standard treatment for acute tendon injuries. The horse should be confined to a stall to minimize movement and allow early healing. After the acute phase, gradual hand-walking begins under veterinary guidance. Return to work is exceptionally slow and gradual, often taking 6-12 months or longer depending on injury severity.

Ice and Cold Therapy

Cold reduces inflammation and pain in the first 48-72 hours after injury. Ice boots, cold water immersion, or ice packs applied for 20 minutes several times daily help minimize swelling. After the acute phase, cold therapy may be used after exercise to reduce post-work inflammation.

Anti-inflammatory Medications

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone (Bute) or firocoxib (Equioxx) reduce inflammation and pain. These are typically used for 7-14 days after acute injury and may be used periodically during rehabilitation. Your veterinarian will recommend appropriate dosing and duration.

Platelet-Rich Plasma (PRP) and Stem Cell Therapy

Regenerative medicine treatments are increasingly used to promote tendon healing. PRP is prepared from the horse’s own blood and contains growth factors that stimulate tissue repair. Stem cell therapy involves injecting cells capable of differentiating into tendon tissue. These treatments, typically administered 2-3 weeks after injury when acute inflammation has resolved, may improve healing quality and reduce the risk of re-injury. These are advanced treatments that add significant cost and require a skilled veterinary specialist to administer.

Corrective Shoeing

Your farrier and veterinarian should work together to ensure the horse’s feet are balanced and supporting the leg correctly during recovery. Rocker-toe shoes or shoes with reduced leverage may be recommended to decrease strain on healing tendons. A well-fitted shoe that addresses underlying conformation or shoeing issues helps prevent re-injury.

Physical Rehabilitation

Gradually increasing exercise during the recovery period is critical to prevent re-injury and restore strength. Hand-walking begins at 1-2 weeks post-injury and progresses very slowly over weeks and months. Controlled trotting typically doesn’t begin until 6-8 weeks after injury, and return to work under saddle often requires 4-6 months or more.

Recovery Timeline and Prognosis

Tendon injury recovery is measured in months, not weeks. The following timeline represents typical expectations for a moderate-severity injury, though individual recovery varies considerably:

Phase	Timeline	Activities and Goals
Acute Injury	Days 1-14	Complete stall rest, ice therapy, anti-inflammatories, initial ultrasound
Early Healing	Weeks 2-6	Limited hand-walking (5-10 minutes), continued stall rest, repeat ultrasound at 4-6 weeks
Progressive Rehabilitation	Weeks 6-16	Gradually increasing hand-walking, short periods of turnout in small paddock, monitoring for setbacks
Return to Light Work	Months 4-6	Walking under saddle, beginning trotting, continued gradual progression
Full Return to Work	6-12+ months	Gradual return to previous activity level; performance horses may require extended recovery

Prognosis depends on the severity of injury, the affected tendon, and the quality of rehabilitation. Minor strains with early treatment may heal sufficiently in 6-8 weeks. Severe tears of the flexor tendons may require 12-18 months of rehabilitation and may never be fully sound for strenuous activity. Some horses return to their previous level of work; others are suitable for light riding or therapeutic purposes. Your veterinarian can provide a more specific prognosis based on ultrasound findings.

Preventing Tendon Injuries

While not all tendon injuries can be prevented, particularly if your horse experiences trauma, several management practices significantly reduce risk:

• Condition gradually: Build fitness and strength over weeks and months. Never return to hard work abruptly after a layoff.
• Maintain proper shoeing: Work with a knowledgeable farrier to keep feet balanced. Reset shoes every 6-8 weeks.
• Evaluate footing: Avoid working excessively on hard surfaces. Provide good quality footing for exercise.
• Warm up and cool down: Spend 10-15 minutes walking and trotting to warm muscles and tendons before intense exercise.
• Monitor workload: Avoid excessive repetitive work. Cross-train to distribute stress across different movements.
• Regular veterinary exams: Have your horse evaluated by a veterinarian at least annually to identify early signs of joint or tendon issues.
• Maintain weight: Overweight horses place additional stress on tendons. Proper nutrition supports tissue health.
• Address conformation issues: Horses with poor conformation benefit from appropriate shoeing and may require restricted activity.

Frequently Asked Questions

How do I know if my horse has a tendon injury versus just inflammation?

Superficial swelling and heat around the tendon area may represent inflammation or early injury. Only ultrasound can definitively show whether tendon fibers are actually damaged. If your horse is lame or shows swelling, have a veterinary examination and ultrasound performed. Do not assume swelling will resolve without evaluation.

Can horses completely recover from tendon injuries?

Many horses do recover well from tendon injuries, but the quality of healing and return to soundness varies. A horse that had a minor strain may become completely sound for light riding. A horse with a severe tear may be suitable for light walk-only work but never gallop or jump safely again. Some horses develop permanent thickening of the tendon even when healed. Your veterinarian’s prognosis based on ultrasound findings will give you realistic expectations.

Is stall rest really necessary for the entire recovery period?

Complete stall rest for the first 2-4 weeks is critical to minimize re-injury during the initial healing phase. After that period, controlled hand-walking and very limited turnout under veterinary guidance are part of normal rehabilitation and actually support healing by encouraging gradual tissue remodeling. However, uncontrolled turnout and jumping or running are not safe until much later in recovery. Your veterinarian will guide when increased activity is appropriate.

What is the cost of treating a tendon injury?

Basic treatment including veterinary examination, ultrasound imaging, and conservative management (rest, medications, farrier work) typically costs $800-$2,500. Regenerative medicine treatments like PRP or stem cell therapy add $1,500-$3,000 or more per injection. MRI imaging, if needed, costs $2,000-$4,000. The extended recovery period also involves ongoing veterinary monitoring, farrier care, and lost riding time. More aggressive regenerative treatments may be justified for high-value horses.

Key Takeaways

• Tendon injuries are common in horses and result from acute trauma, overuse, or gradual wear. Flexor tendons in the lower leg are most frequently affected.
• Sudden lameness, swelling, and heat warrant immediate veterinary evaluation. Ultrasound is the primary diagnostic tool and shows the location and extent of injury.
• Treatment includes stall rest, anti-inflammatory medication, regenerative therapy, corrective shoeing, and extremely gradual rehabilitation over 6-12+ months.
• Prognosis varies widely depending on injury severity and location. Some horses return to full soundness; others are suitable only for light work.
• Prevention through gradual conditioning, proper shoeing, appropriate footing, and careful workload management significantly reduces injury risk.
• Never rush rehabilitation. Premature return to work is the most common cause of re-injury and complications.