Ligament Injuries

Ligaments are strong bands of connective tissue that help support and stabilise the horse's joints and control movement. Injuries can range from relatively minor fibre damage to severe tearing or rupture.

A horse may be diagnosed with a suspensory ligament injury, proximal suspensory desmitis, collateral ligament injury, check ligament injury or another ligament problem. These names can sound complicated, but understanding where the affected structure is and what it normally does can make the diagnosis much easier to understand.

Ligament injuries can happen suddenly, perhaps following a slip, awkward landing or excessive loading, or develop gradually through repeated strain.

Some cause obvious changes in the horse's movement, while others may initially appear only as subtle changes in performance, behaviour or willingness to work.

What are ligaments?

Ligaments are tough, fibrous structures that generally connect and support bones around joints and help control the amount and direction of movement.

They are designed to tolerate considerable forces. As the horse moves, different ligaments help stabilise joints and prevent structures moving beyond their normal range.

If the forces placed upon a ligament exceed what its fibres can tolerate, some of those fibres may become damaged.

The severity can vary enormously. There may be a relatively small area of fibre damage, more extensive tearing or, in severe cases, complete rupture.

The effect on the horse therefore depends not simply on having a "ligament injury", but on which ligament has been damaged, where the damage is and how extensive it is.

Understanding some common ligament injury diagnoses

Veterinary terminology can sometimes make a diagnosis sound more complicated than it really is.

The following are some of the terms horse owners commonly hear and, in everyday language, what they actually mean.

Suspensory ligament injury

The suspensory ligament runs down the back of the cannon bone and forms part of an important supporting system for the fetlock.

Think of it as part of the horse's natural support and spring mechanism.

When the horse puts weight onto the limb, the fetlock moves downwards towards the ground. The suspensory apparatus helps control this movement and supports the fetlock as considerable forces pass through the limb.

When the suspensory ligament is injured, some of its fibres have been damaged. This can reduce its ability to tolerate and control those forces comfortably.

You may hear different descriptions depending upon where the damage is located.

Proximal suspensory injury or proximal suspensory desmitis — PSD

This means that the injury is towards the upper part, or origin, of the suspensory ligament, close to where it begins below the knee in the forelimb or below the hock in the hindlimb.

"Proximal" simply means towards the upper or origin end of the structure.

Suspensory body injury

This means that the damage is within the main section of the suspensory ligament running down the cannon region.

Suspensory branch injury

Lower down the limb, the suspensory divides into branches associated with the fetlock region.

A suspensory branch injury means that one or both of these branches have been damaged.

Although all three may be described generally as "suspensory injuries", their location and severity can affect the signs the horse shows, rehabilitation and prognosis.

Collateral ligament injury

Collateral ligaments are found at the sides of joints and help prevent excessive sideways or twisting movement.

Think of them as strong stabilising straps that help keep a joint moving within its intended range.

When a collateral ligament is damaged, loading or moving the joint in particular directions may become uncomfortable.

This can be one reason why some ligament injuries become more noticeable when a horse is turning, working on a circle or travelling over uneven ground.

Collateral ligament injuries can occur at several joints. Owners may particularly hear the term used in relation to the coffin joint inside the hoof, where the injured ligament cannot necessarily be seen or felt from the outside.

Check ligament injury

The structure commonly called the check ligament is associated with the horse's flexor tendon system.

It helps support that system and limits excessive movement as substantial forces pass through the lower limb.

When the check ligament is injured, fibres within it may become strained or torn. Heat or swelling may sometimes be apparent, although the signs and significance depend upon the location and severity of the damage.

Your vet may use the anatomical term accessory ligament of the deep digital flexor tendon or refer to the inferior check ligament.

Annular ligament problems

The annular ligaments are strong bands of tissue that help hold the flexor tendons close to the limb as they pass through particular areas.

They can be thought of rather like a retaining strap or sleeve that helps keep the tendons correctly positioned while still allowing them to move.

If an annular ligament becomes thickened or constricted, there may be less room for the tendons and surrounding structures to move normally.

Annular ligament problems can therefore sometimes occur alongside inflammation or injury involving the tendons or tendon sheath.

Other ligament injuries

The horse has many other ligaments supporting structures including the fetlock, pastern, coffin joint, hock and stifle.

The names and locations differ, but the basic principle remains similar: a structure whose normal job is to support, stabilise or control movement has been damaged.

That is why knowing exactly which ligament is involved is important.

What does "desmitis" mean?

This is a word owners frequently encounter on veterinary reports.

Desmitis means inflammation involving a ligament and is commonly used when describing ligament injury.

For example:

Proximal suspensory desmitis

can be understood as:

Proximal — towards the upper/origin end
Suspensory — the suspensory ligament
Desmitis — inflammation involving a ligament

So in everyday language, the diagnosis is describing a problem affecting the upper part of the suspensory ligament.

Understanding the terminology cannot tell you how serious an individual horse's injury is, but it can make it much easier to understand what your vet is describing.

What can cause a ligament injury?

Ligament injuries may result from a single incident or develop through repeated loading over time.

Possible contributing factors include:

• slipping or losing footing;
• twisting or turning suddenly;
• landing awkwardly;
• working on uneven, deep or unsuitable surfaces;
• repetitive loading during training or competition;
• fatigue, which may reduce the horse's ability to control and stabilise movement;
• hoof balance or other factors that alter how forces pass through the limb;
• returning to demanding work before tissues are adequately conditioned;
• previous injury or instability affecting the area.

Sometimes there is no obvious incident at all.

An owner may simply become aware that their horse is moving differently, no longer performing as expected or is reluctant to do something that was previously comfortable.

What might an owner notice?

The signs depend upon which ligament is affected, where it is located and the severity and age of the injury.

An owner may notice:

• heat or swelling;
• sensitivity when an area is touched;
• a change in the horse's normal movement;
• uneven timing between limbs;
• reluctance to turn tightly or work on a circle;
• difficulty on particular surfaces;
• reduced willingness to jump, extend or perform particular movements;
• stiffness when first moving;
• deterioration in performance;
• changes that become more noticeable during or after exercise.

Not every ligament injury produces obvious external swelling, particularly when the affected structure is deep within the limb or hoof.

Does the horse actually take a shorter stride?

People commonly describe an affected horse as having a "shortened" or "choppy" stride.

What we see, however, can be more complicated.

For a horse to continue moving and remain coordinated, the limbs have to work together. An apparent shortening on one side may actually result from changes in timing, loading, weight transfer and how long the horse spends in different phases of the stride.

The horse may unload an uncomfortable limb sooner, alter the timing of the opposite limb or change the way the whole body moves.

To the observer this can look like a shorter stride, but what we are often seeing is the horse changing the way it uses its limbs to manage discomfort or instability.

This is one reason observing movement is useful, but does not by itself tell us which structure is injured.

How are ligament injuries diagnosed?

A veterinary examination is important because altered movement can have many different causes.

The location of the problem cannot reliably be determined simply by watching the horse.

Assessment may include examination at rest, palpation of the limbs and observing the horse moving under different circumstances.

Depending upon the suspected location, further investigation may include:

• diagnostic analgesia, commonly known as nerve or joint blocks;
• ultrasound;
• radiography;
• MRI;
• other diagnostic imaging where appropriate.

Imaging can help the veterinary surgeon identify which structure is affected, where within that structure the injury is located and the extent of the damage.

These findings can be important when planning rehabilitation and discussing prognosis.

Treatment and rehabilitation

There is no single rehabilitation programme suitable for every ligament injury.

Management depends upon the ligament involved, the location and severity of the damage, the horse's age and intended use and the findings of veterinary examination and diagnostic imaging.

Treatment may initially involve restricted activity followed by a carefully controlled programme of rehabilitation.

Rather than simply resting a horse for a predetermined number of weeks or months and then returning to normal work, rehabilitation is generally progressive.

Exercise is gradually increased as healing allows.

Veterinary reassessment and, in some cases, repeat imaging may be used to evaluate healing and help determine when exercise can safely progress.

The aim is not simply to reach the point where the horse appears comfortable.

The injured tissue needs sufficient time to repair, remodel and progressively adapt to the forces it will encounter during future work.

Returning to demanding exercise before the tissue is ready may increase the risk of reinjury.

Why controlled exercise can matter

Complete rest and appropriate rehabilitation are not necessarily the same thing.

During later stages of healing, carefully controlled loading can form an important part of helping repairing tissue organise and adapt.

However, too much loading too soon can damage healing tissue.

The balance between protection and appropriate exercise therefore needs to be determined for the individual injury.

This is why an exercise programme prescribed for one horse with a suspensory injury should not automatically be copied for another horse simply because the diagnosis sounds similar.

Hoof balance and limb loading

The hoof is the point through which forces from the ground enter the limb.

Hoof balance, trimming or shoeing cannot repair a damaged ligament, but appropriate hoof care may be an important part of the overall management of some injuries.

Where relevant, the veterinarian and farrier can work together to consider how the foot is landing and loading and whether changes to trimming or shoeing could help manage the forces passing through the affected structures during rehabilitation.

Any changes should be appropriate to the individual horse and diagnosed injury, rather than applying the same trimming or shoeing approach to every ligament problem.

Supporting the whole horse during rehabilitation

Rehabilitation is about more than the injured ligament.

A horse whose exercise has been substantially reduced may require changes to its feeding and general management.

Maintaining an appropriate bodyweight can help avoid unnecessary additional loading of the limbs.

The diet should continue to provide adequate high-quality protein, vitamins and minerals to support normal tissue maintenance and repair while avoiding unnecessary excess energy when workload is reduced.

Controlled exercise, turnout and changes in workload should follow the rehabilitation programme recommended for the individual horse.

Owners should also continue to monitor the horse carefully.

New heat, swelling, discomfort or deterioration in movement during rehabilitation should be discussed with the treating veterinary surgeon rather than simply continuing to increase exercise.

Can ligament injuries heal?

Ligaments can heal, but healing connective tissue does not necessarily return to exactly the same structure it had before the injury.

Repair tissue develops and gradually remodels.

This process takes time, and the developing tissue needs to become capable of coping with progressively greater forces.

This is one reason rehabilitation from significant ligament injuries can take many months rather than weeks.

The outlook varies considerably depending upon:

• the ligament involved;
• where within it the damage has occurred;
• the extent of the injury;
• whether surrounding structures are also affected;
• the horse's intended level of work;
• the response to treatment and rehabilitation;
• whether reinjury occurs.

The diagnosis "ligament injury" therefore does not by itself tell an owner what the eventual outcome will be.

When should I contact my vet?

Seek veterinary advice if your horse develops:

• a sudden or significant alteration in movement;
• obvious pain or reluctance to bear normal weight;
• new heat or swelling;
• persistent or recurring changes in movement;
• unexplained deterioration in performance;
• discomfort following a slip, fall or other incident;
• deterioration during rehabilitation from a known injury.

Severe ligament injuries can compromise the stability of a joint or supporting structures and may require prompt veterinary assessment.

If you are uncertain about a change in your horse's movement, it is better to have the cause investigated rather than attempting to identify the affected structure yourself.

Suggested Graphics

Graphic 1 — Hero Graphic: “Understanding Ligament Injuries”

Visual concept:
An anatomically accurate horse in side view with one limb enlarged alongside it. Show the general position of important ligament structures, with particular emphasis on the suspensory apparatus without implying that all ligament injuries involve the suspensory ligament.

Standalone text:

LIGAMENT INJURIES

Ligaments support and stabilise the horse's joints and help control movement.

Injury can range from relatively minor fibre damage to severe tearing or rupture.

You may hear terms including:

Suspensory ligament injury • PSD • Collateral ligament injury • Check ligament injury

The name tells us which structure has been affected. The location and extent of the damage help determine what the injury means for the individual horse.

JCG Health Hub | jcgsupplements.com

The JCG identity and website address must remain clearly visible if the graphic is downloaded, printed or shared independently.

Graphic 2 — “Understanding a Suspensory Injury”

Visual concept:
A clear lower-limb anatomical illustration showing the suspensory ligament from its origin down the back of the cannon region and its division into the suspensory branches.

Label:

Proximal suspensory region
↓
Suspensory body
↓
Suspensory branches
↓
Fetlock support

Include a small second illustration showing the fetlock moving downwards as the limb accepts weight.

Standalone text:

THE SUSPENSORY LIGAMENT — WHAT DOES IT DO?

Think of the suspensory apparatus as part of the horse's natural support and spring mechanism.

As the horse loads the limb, the fetlock moves downwards. The suspensory apparatus helps support and control this movement.

A suspensory injury means fibres within this supporting structure have been damaged.

Proximal suspensory injury / PSD — upper part
Suspensory body injury — main central section
Suspensory branch injury — lower branches around the fetlock region

The location and severity of an injury influence rehabilitation and prognosis.

JCG Health Hub | jcgsupplements.com

This graphic should be sufficiently anatomically accurate and informative to be printed or shared independently without requiring the accompanying webpage.

Graphic 3 — “Ligament Rehabilitation Is Progressive”

Visual concept:
A clean horizontal progression showing:

DIAGNOSIS → PROTECTION → CONTROLLED EXERCISE → GRADUAL LOADING → REASSESSMENT → RETURN TO WORK

Below it:

Healing isn't simply waiting.

Repairing ligament tissue needs time to develop, remodel and gradually adapt to increasing forces.

Too much loading too soon may damage healing tissue.

Rehabilitation should therefore be based upon the individual injury and veterinary assessment rather than a fixed timetable.

JCG Health Hub | jcgsupplements.com

The JCG identity and website address must remain visible if the graphic is printed or shared independently.

JCG Health Hub information is intended to help horse owners understand equine health and management. It does not replace examination, diagnosis or treatment by a veterinary surgeon. If you are concerned about your horse, seek appropriate veterinary advice.