Understanding Equine Stringhalt and How to Help

By Dr Duncan Houston

Stringhalt is one of those conditions that can look alarming the first time you see it.

A horse suddenly snatches a hind leg upward in an exaggerated, jerky motion, almost as if the limb is being pulled by a string. In mild cases it may only show up when the horse turns or backs up. In more severe cases, it can interfere with normal movement and make the horse look dramatically unsound.

The good news is that not every case is severe, and not every case carries the same outlook.

Some horses improve with simple management changes, especially when pasture-related causes are involved. Others need a more detailed workup because similar gait abnormalities can also point to orthopedic or neurologic disease.

This article explains what stringhalt is, what causes it, how vets approach diagnosis, and what treatment and long-term management can realistically achieve.

Quick Answer

Stringhalt is a hind limb gait abnormality in horses that causes exaggerated flexion of one or both hind legs, especially at the walk, while turning, or when backing up. Some cases are pasture-associated and may improve after removal from the offending environment, while others are idiopathic and may persist or require medical or surgical management. The key is confirming the diagnosis and ruling out other causes of abnormal hind limb movement.

Quick Decision Guide

Horse shows a mild high-stepping hind limb motion mainly when turning or backing up, but otherwise seems comfortable → mild stringhalt is possible and should be assessed

Horse recently grazed poor-quality or drought-affected pasture and more than one horse is affected → pasture-associated stringhalt moves higher on the list

Horse has worsening gait abnormality, weakness, stumbling, or other neurologic signs → broader neurologic or orthopedic disease must be ruled out

Horse is severely affected and struggles with normal movement → veterinary assessment is needed promptly

Sudden abnormal hind limb gait after injury or trauma → do not assume stringhalt without a full examination

What Is Stringhalt?

Stringhalt is a neuromuscular gait abnormality characterized by exaggerated flexion of the hind limb.

In practical terms, the horse lifts the hind leg too high and too abruptly during movement. This often looks worse at slower gaits and may be especially obvious when:

• walking

• turning

• backing up

One hind limb is commonly affected, but both can be involved.

What makes stringhalt distinctive is not just that the gait is abnormal. It is the sharp, exaggerated flexion pattern, especially compared with more ordinary lameness or stiffness.

What This Usually Turns Out To Be

When owners notice a horse suddenly lifting one hind leg high in a jerky motion, the situation usually falls into one of these:

• true stringhalt

• pasture-associated stringhalt linked to toxic plant exposure

• a neurologic gait abnormality that looks similar

• an orthopedic issue affecting hind limb use

• a less common neuromuscular disorder

The mistake I see most often is assuming every odd hind limb movement is stringhalt.

It may be, but the more important question is why the horse is moving that way.

Types of Stringhalt

There are two main patterns people usually talk about.

Idiopathic Stringhalt

This form has no clearly identified cause.

It may affect one or both hind limbs and can persist for long periods. Some cases remain mild and manageable. Others are more severe and may interfere with the horse’s comfort or usefulness.

Pasture-Associated Stringhalt

This form is linked to grazing certain toxic plants, especially in poor-quality, overgrazed, or drought-stressed pasture.

This version often appears in clusters or in horses that have been exposed to similar pasture conditions.

The important practical difference is that pasture-associated cases often improve once the horse is removed from the source.

Decision Checkpoint

If the horse developed signs after grazing poor pasture, especially in dry seasons or when forage was limited, pasture-associated stringhalt becomes much more likely.

Plants Linked to Pasture-Associated Stringhalt

Pasture-associated stringhalt has been linked to toxic plants including:

• false dandelion

• sweet pea and related plants

These plants are more likely to be eaten when:

• pasture quality is poor

• grazing is overused

• drought limits normal forage availability

• horses are bored or hungry enough to eat plants they would usually avoid

This is why pasture management matters so much.

The issue is often not just the plant itself. It is the conditions that made the horse eat it.

What Vets Care About Most

When assessing a possible stringhalt case, the most important questions include:

• is one leg affected or both

• how severe is the exaggerated flexion

• does it worsen when backing up or turning

• did the problem appear after pasture changes

• are there other neurologic or orthopedic signs

• are multiple horses on the property affected

What matters most is separating true stringhalt from other causes of hind limb abnormality.

How Stringhalt Is Diagnosed

Diagnosis is usually based on:

• watching the horse walk

• observing turns and backing up

• performing a neurologic examination

• reviewing pasture and seasonal history

• ruling out other causes of abnormal gait

Additional tests may be needed when the picture is not straightforward.

These can include:

• bloodwork

• imaging

• broader lameness evaluation

• neurologic workup

The diagnosis is often strongly clinical, but the real work is making sure it is not something else.

What Conditions Need To Be Ruled Out?

Not every high-stepping hind limb gait is stringhalt.

Important rule-outs can include:

• trauma

• stifle or hock pain

• upward fixation of the patella

• neurologic disease

• spinal issues

• generalized weakness or coordination problems

This is why a horse with abnormal hind limb movement should not be diagnosed casually from appearance alone.

How Severe Can It Be?

Stringhalt can range from mild and intermittent to dramatic and function-limiting.

Mild

• only visible at the walk

• mainly obvious when backing up or turning

• horse otherwise moves reasonably well

Moderate

• exaggerated flexion is more obvious in daily movement

• may interfere with flatwork or athletic use

• horse appears clearly unsound

Severe

• marked abnormal hind limb action

• difficulty moving normally

• poor suitability for riding or competition

• greater concern for long-term usability and safety

Some horses stay stable. Others worsen. That is why monitoring matters.

Treatment Options

Treatment depends on the likely cause and severity.

Remove the Horse From Suspect Pasture

For pasture-associated cases, this is the first and most important step.

That means:

• removing the horse from the affected paddock

• identifying and reducing toxic plant exposure

• providing clean forage and adequate hay

• improving pasture quality and grazing management

This alone can lead to improvement in many pasture-related cases.

Medical Management

Some cases are managed with supportive medical options such as:

• thiamine

• phenytoin in selected cases

Response varies, and these treatments are not magic fixes.

Surgical Management

In more severe or persistent idiopathic cases, surgery such as lateral digital extensor tenectomy may be considered.

This is generally reserved for cases where:

• gait abnormality is significant

• function is clearly affected

• conservative management has not been enough

Not every horse responds, and surgery should be seen as a selective option rather than a guaranteed cure.

Can Horses With Stringhalt Still Be Ridden?

Sometimes, yes.

This depends on:

• severity

• whether one or both hind limbs are affected

• how comfortable and coordinated the horse is

• what type of work is expected

Many mildly affected horses can still do:

• light riding

• trail work

• lower-intensity flat work

More severely affected horses may be unsuitable for demanding work or competition.

The real question is not whether the condition has a name. It is whether the horse can move safely and comfortably for the job being asked of it.

Common Mistakes Owners Make

Some of the most common mistakes include:

• assuming the horse will simply “walk out of it”

• missing the pasture link in affected horses

• delaying investigation when the gait worsens

• pushing on with work in a more severe case

• assuming all abnormal hind limb action is stringhalt

The biggest mistake is focusing only on the dramatic movement and not on the cause behind it.

What Should You Do Right Now?

If you think your horse may have stringhalt:

1. Record a clear video of the horse walking, turning, and backing up

2. Review any recent pasture or forage changes

3. Check whether other horses on the property are affected

4. Arrange a veterinary assessment

5. Remove the horse from suspect poor-quality pasture if pasture-associated disease is possible

6. Avoid pushing harder work until the diagnosis is clearer

Simple checkpoint:

mild abnormal hind limb flexion + pasture risk → think pasture-associated stringhalt

worsening gait or additional neurologic signs → broader investigation needed

When Is This an Emergency?

Stringhalt itself is not always an emergency, but urgent assessment is needed if:

• the gait abnormality is rapidly worsening

• the horse is unsafe to move or ride

• there are additional neurologic signs

• weakness, stumbling, or collapse are present

• trauma could be involved

These situations go beyond routine monitoring.

Prevention and Long-Term Management

Long-term prevention focuses mainly on pasture management.

That includes:

• avoiding overgrazing

• maintaining adequate forage availability

• identifying toxic plants

• checking drought-stressed paddocks carefully

• rotating and improving pasture condition

This matters because many pasture-associated cases are linked not just to toxic plants, but to management situations that make those plants more likely to be eaten.

Frequently Asked Questions

What does stringhalt look like in a horse?
It usually causes exaggerated, jerky flexion of one or both hind limbs, especially at the walk, while turning, or when backing up.

Can pasture cause stringhalt?
Yes. Some cases are linked to toxic plants in poor-quality or drought-affected pasture.

Does stringhalt always get worse?
No. Some cases stay mild, and pasture-associated cases may improve once exposure stops.

Can horses recover from stringhalt?
Some can improve significantly, especially pasture-associated cases. Others may remain affected long term.

Can a horse with stringhalt still be ridden?
Mild cases sometimes can. Severe cases may not be suitable for safe or demanding work.

Final Thoughts

Stringhalt looks strange, but it is not the same in every horse.

Some cases are mild and manageable. Some improve with pasture changes. Some need more involved medical or surgical decisions. The key is not panicking at the appearance of the gait, but not dismissing it either.

If your horse is suddenly moving with exaggerated hind limb flexion, the right response is to step back, assess the pattern, review the pasture, and get a proper diagnosis.

If you want help working through whether your horse’s gait change looks like stringhalt, pasture-associated disease, or something else, ASK A VET™ can help you think through the next step clearly and practically.