Sacroiliac Pain in Horses: Signs, Diagnosis and Management

By Dr Duncan Houston

Sacroiliac pain can make a horse feel weak behind, resistant in canter, uneven under saddle, or simply “not right.”

Sacroiliac pain is one of the more frustrating causes of poor performance in horses because it often hides behind vague signs. The horse may not look obviously lame on a straight line. The back may not react dramatically to palpation. The problem may only show when the horse is ridden, asked to canter, sit, collect, jump, turn, or push from behind.

That is why sacroiliac pain is often missed, overcalled, or lumped into the very unhelpful category of “back problem.”

The key is understanding that sacroiliac pain is not diagnosed from one sign. A horse carrying the tail to one side, bunny hopping in canter, or tracking narrow behind does not automatically have sacroiliac pain. The diagnosis needs a proper lameness and performance workup, because sacroiliac region pain commonly occurs alongside other problems such as proximal suspensory pain, stifle pain, hock pain, thoracolumbar pain, poor saddle fit, rider asymmetry, or true hindlimb lameness.

Quick Answer

Sacroiliac pain in horses refers to pain from the sacroiliac joint region, where the pelvis connects to the sacrum at the base of the spine. It can cause poor hindlimb impulsion, trunk stiffness, difficulty in canter, bucking or kicking out in canter, reduced performance, and a horse that feels weaker behind. In a study of 296 horses with sacroiliac region pain, signs were more obvious during ridden work than lunging, and many horses had concurrent sources of pain rather than isolated sacroiliac pain. (EquiManagement)

A horse with suspected sacroiliac pain should have a full veterinary lameness and back assessment. Imaging can help, but negative ultrasound or scintigraphy does not rule it out, and diagnostic analgesia of the sacroiliac region is useful but not perfectly specific. (EquiManagement)

What Is the Sacroiliac Joint?

The sacroiliac joints sit deep within the pelvis, where the wings of the ilium connect to the sacrum. In a horse, this region helps transfer force from the powerful hindlimbs through the pelvis and into the spine and trunk.

That matters because every stride, jump, transition, hill, tight turn, collected movement, and canter departure asks the horse to stabilise and transmit power through this area.

When the sacroiliac region is painful, the horse may protect itself by reducing hindlimb push, stiffening the trunk, avoiding collection, resisting canter, or changing the way it tracks behind.

The important wording is sacroiliac region, not just sacroiliac joint. Pain may come from the joint itself, the surrounding ligaments, the lumbosacral region, adjacent soft tissues, or several overlapping structures. This is one reason diagnosis is difficult. A PLOS One study notes that true sacroiliac joint pain can be difficult to separate from more general lumbosacral region pain, and that local anaesthetic technique and volume can influence what structures are desensitised. (PLOS)

Why Sacroiliac Pain Is So Hard To Diagnose

Sacroiliac pain is difficult because the region is deep, heavily muscled, hard to image, and often involved with other causes of lameness.

The big diagnostic problems are:

• The joint cannot be reliably assessed from surface palpation alone
• Signs are often worse under saddle than in hand
• Imaging may be normal even when the region is painful
• Diagnostic blocks help, but are not perfectly specific
• Many horses also have hock, stifle, proximal suspensory, foot, back, or saddle related pain
• Riders often feel the problem before it becomes obvious on a lameness exam

In the 296 horse study, only 43 horses had sacroiliac region pain alone, while 253 also had other sources of pain. That is a huge clinical clue: if a horse has suspected sacroiliac pain, the vet should not stop looking once the SI region is suspected. (EquiManagement)

In another study of horses undergoing sacroiliac region analgesia, proximal suspensory ligament pain and stifle joint pain were frequently identified alongside sacroiliac region pain, reinforcing that these cases are often multifactorial. (PLOS)

Signs of Sacroiliac Pain in Horses

Sacroiliac pain can look subtle, especially early.

Owner reported signs may include:

• Reduced impulsion from behind
• Difficulty engaging the hindquarters
• Canter feeling worse than trot
• Trouble striking off into canter
• Disunited canter
• Bunny hopping feeling in canter
• Bucking or kicking out during canter transitions
• Resistance to collection
• Reluctance to jump
• Poor bascule or reduced power over fences
• Drifting, crookedness, or falling in on circles
• Tail held to one side
• Reduced topline or gluteal muscle
• Stiffness through the back or trunk
• Shorter hindlimb stride
• Difficulty going downhill
• Poor performance without obvious forelimb lameness

In the large sacroiliac region pain study, horses with isolated sacroiliac region pain commonly showed trunk stiffness during exercise, poor hindlimb impulsion, increased longissimus dorsi muscle tension, restricted thoracolumbar flexibility, worse canter than trot, and in some cases bucking or kicking out during canter. (EquiManagement)

The most important practical point is this:

Sacroiliac pain usually becomes more obvious when the horse is asked to use the hindquarters properly.

That is why owners often report that the horse is “fine hacking” but not fine in collected work, canter transitions, jumping, lateral work, hills, or circles.

Signs Under Saddle Matter

A horse with sacroiliac region pain may look only mildly abnormal on a lunge line but feel very wrong under saddle.

In the 296 horse study, clinical signs were seen in a significantly greater proportion of horses during ridden work than during lunging. That is important because a horse can look deceptively acceptable in a simple trot up, then show the real problem when ridden. (EquiManagement)

This is why the best assessment often includes:

• Straight line in hand
• Circles on both reins
• Lunge on soft and firm surfaces where safe
• Ridden assessment
• Walk, trot, canter, transitions, circles, and lateral work if appropriate
• Rider feedback about how the horse feels
• Comparison before and after diagnostic blocks when indicated

The rider’s description matters, but it still needs veterinary interpretation. “He feels weak behind” is useful. It is not a diagnosis.

Sacroiliac Pain Risk Framework

Risk level	What it looks like	What it may mean	What to do
Low risk	Mild stiffness, horse still comfortable, no obvious lameness, improves with warm up	Early soreness, fitness issue, saddle issue, or mild compensation possible	Monitor closely, review workload, saddle fit, hoof balance, and book a vet check if it persists beyond 1 to 2 weeks
Moderate risk	Poor canter, reduced hindlimb impulsion, tail crookedness, resistance to collection, mild unevenness	Sacroiliac region pain or another hindlimb/back issue possible	Arrange a veterinary lameness and ridden assessment
High risk	Bucking in canter, marked hindlimb weakness, clear performance decline, muscle asymmetry, recurrent poor response to training	Significant pain or multiple orthopaedic problems possible	Full diagnostic workup, including limb lameness investigation and back assessment
Critical	Sudden severe hindlimb lameness, fall or trauma, ataxia, inability to stand, severe pelvic asymmetry, fever, severe pain, neurologic signs	Emergency injury, pelvic fracture, neurologic disease, severe lameness, or systemic illness possible	Call a veterinarian urgently and do not ride or force movement

The decision point is simple: subtle poor performance can be scheduled for a workup, but sudden severe pain, weakness, trauma, or neurologic signs are urgent.

When Is This an Emergency?

Sacroiliac pain itself is usually not an emergency when it develops gradually. But some conditions that mimic sacroiliac pain are emergencies.

Call your veterinarian immediately if your horse has:

• Sudden severe hindlimb lameness
• Recent fall, slip, collision, or cast episode
• Inability or reluctance to bear weight
• Ataxia or wobbliness
• Weakness that looks neurologic
• Inability to rise
• Severe pelvic asymmetry after trauma
• Fever with back or hindquarter pain
• Severe muscle pain or dark urine
• Colic signs with hindlimb weakness
• Rapid deterioration over hours
• New urine dribbling or tail tone loss

Do not assume a horse has “put its back out” after a fall. Pelvic fractures, neurologic disease, exertional rhabdomyolysis, severe hindlimb lameness, and systemic illness can all create signs that owners may describe as back end weakness.

What Else Can Look Like Sacroiliac Pain?

This is where the article earns its keep.

Sacroiliac pain is a possibility, not a default diagnosis. Many other problems can look similar.

Important rule outs include:

• Proximal suspensory desmitis
• Hock osteoarthritis
• Stifle pain
• Foot pain
• Pelvic fracture or stress injury
• Thoracolumbar back pain
• Kissing spines
• Lumbosacral pain
• Gluteal muscle strain
• Hamstring or semimembranosus or semitendinosus injury
• Saddle fit problems
• Rider asymmetry
• Poor hoof balance
• Poor conditioning
• Neurologic disease
• Shivers
• Equine protozoal myeloencephalitis in relevant regions
• Equine herpesvirus myeloencephalopathy
• West Nile virus in relevant regions
• Exertional rhabdomyolysis
• Behavioural resistance from pain elsewhere

The mistake I see most often is treating the sacroiliac region while missing the real driver of the problem.

A horse with hock pain may protect the hindquarters and become sore through the back. A horse with proximal suspensory pain may lose push and feel weak behind. A horse with a poorly fitting saddle may brace the thoracolumbar region and resist canter. A horse with neurologic disease may look “weak behind” but needs a very different plan.

That is why the diagnosis should start broad, then narrow.

How Do Vets Diagnose Sacroiliac Pain?

A good workup usually includes several layers.

1. History

Your vet will ask:

• When did the problem start?
• Was there a fall, slip, jump, travel event, or training change?
• Is the horse worse in canter, collection, jumping, hills, or circles?
• Is the issue one-sided or both-sided?
• Is the horse worse under saddle than on the lunge?
• Has the horse had hock, stifle, suspensory, foot, or back problems before?
• Has saddle fit changed?
• Has the rider changed?
• Is there muscle loss over the croup or topline?
• Does rest improve it?
• Does harder work make it worse?

The history often tells you whether this is likely a primary sacroiliac issue, secondary compensation, poor conditioning, or a broader lameness problem.

2. Physical and back examination

The vet will assess:

• Back muscle tone
• Pelvic symmetry
• Tuber sacrale height and shape
• Gluteal muscle development
• Pain response to palpation
• Thoracolumbar flexibility
• Tail tone and carriage
• Range of motion
• Hindlimb muscle symmetry
• Neurologic signs

Palpation can identify discomfort, muscle tension, asymmetry, or guarding, but it cannot confirm sacroiliac pain by itself.

3. Lameness examination

The horse may be assessed:

• At walk and trot in hand
• On circles
• On hard and soft surfaces
• Under saddle
• In canter
• During transitions
• Over poles or fences if appropriate
• Before and after flexion tests where relevant

Merck Veterinary Manual describes regional anaesthesia as a valuable diagnostic aid for localising lameness when the origin of pain remains uncertain, allowing imaging and further tests to be used more effectively. (Merck Veterinary Manual)

4. Diagnostic analgesia

Diagnostic analgesia means numbing a region to see whether the horse improves. For suspected sacroiliac pain, sacroiliac region analgesia may be used in referral or experienced lameness settings.

This can be very useful, but it needs careful interpretation.

A positive response supports pain from the sacroiliac or lumbosacral region, but it does not always prove the exact structure. PLOS One notes that sacroiliac region pain can only be supported by response to diagnostic local analgesia or infiltration, but that differentiating true sacroiliac joint pain from more general lumbosacral region pain can be difficult. (PLOS)

The same study found complications after sacroiliac region analgesia were uncommon using the described technique, with a low complication prevalence of 0.85%, but possible complications include ataxia and recumbency. (PLOS)

Translation: useful test, not a casual backyard procedure.

5. Imaging

Imaging may include:

• Ultrasound
• Rectal ultrasound in selected cases
• Nuclear scintigraphy
• Radiography in selected pelvic or spinal cases
• CT in rare referral situations
• Other imaging based on suspected concurrent disease

The challenge is that imaging does not always give a clean answer. In the 296 horse study, abnormal radiopharmaceutical uptake in the sacroiliac region was seen in 47% of horses that underwent scintigraphy, while per rectum ultrasonography found abnormalities in 32% of horses examined. The authors also noted that negative ultrasound or scintigraphy results do not rule out sacroiliac region pain. (EquiManagement)

This is the key imaging lesson:

Positive imaging can help. Negative imaging does not always clear the sacroiliac region.

Can Sacroiliac Pain Be Confirmed From Gait Alone?

No.

Gait signs can raise suspicion, but they cannot confirm the diagnosis.

A horse that tracks narrow behind, carries the tail to one side, bunny hops in canter, or struggles with canter transitions may have sacroiliac pain. But those same signs can also occur with hock pain, stifle pain, proximal suspensory pain, back pain, saddle problems, neurologic disease, weakness, or training issues.

In practice, gait signs are clues.

The diagnosis needs a structured workup.

A single Instagram-style checklist is not enough. Very convenient, yes. Clinically risky, also yes.

How Is Sacroiliac Pain Treated?

Treatment depends on whether the sacroiliac region is the main problem or part of a wider pain pattern.

A good plan usually combines pain control, treating concurrent lameness, rehabilitation, saddle and rider assessment, and gradual return to work.

1. Treat the real source of pain

If the horse also has hock arthritis, stifle pain, proximal suspensory desmitis, foot pain, kissing spines, or saddle-related pain, those need to be addressed.

Injecting or treating the sacroiliac region while ignoring a painful suspensory ligament is like repainting a fence while the gate is falling off. Something changed, but not the thing that mattered.

2. Controlled rest and workload reduction

Some horses need a period of reduced work, especially if signs are acute or severe.

This does not usually mean months of standing still with no plan. Prolonged rest without progressive strengthening can leave the horse weaker and more vulnerable when work restarts.

The right rest plan depends on severity, diagnosis, concurrent injuries, and the horse’s job.

3. Medication or injections

Your veterinarian may consider:

• NSAIDs for short-term pain and inflammation control
• Sacroiliac region corticosteroid injections
• Ultrasound-guided or landmark-guided injections depending on the case
• Treatment of hocks, stifles, suspensories, or back if those are involved
• Other therapies where appropriate

A review on sacroiliac pain management notes that treating underlying or additional issues is essential, and that medication of the sacroiliac region with corticosteroid may provide temporary improvement while rehabilitation addresses function. (CABI Digital Library)

The important word is temporary.

Injections can reduce pain and inflammation, but they are not a full rehabilitation plan.

4. Rehabilitation and strengthening

Rehab is often the most important long-term piece.

A gradual rehab plan may include:

• In-hand walking
• Straight lines before circles
• Progressive hill work when appropriate
• Core activation exercises
• Backing up exercises
• Belly lifts and pelvic tucks where appropriate
• Raised poles later in rehab
• Long and low work
• Gradual transitions
• Slow reintroduction of canter
• Careful return to jumping or collection
• Regular reassessment

The goal is not just to make the horse less sore.

The goal is to restore strength, symmetry, hindlimb control, trunk stability, and confidence.

5. Physiotherapy and bodywork

Physiotherapy may help improve:

• Core strength
• Flexibility
• Muscle symmetry
• Pelvic stability
• Thoracolumbar mobility
• Hindlimb coordination
• Comfort during return to work

This should support the veterinary diagnosis, not replace it.

If the horse is still lame or neurologic, bodywork alone is not enough.

6. Saddle fit and rider symmetry

Saddle and rider factors can contribute to back and pelvic pain.

Review:

• Saddle fit
• Tree width
• Panel contact
• Saddle slipping
• Rider sitting crooked
• Rider collapsing through one hip
• Uneven stirrup length
• Horse changing shape during rehab
• Fit changes after muscle loss or gain

A good saddle on a poorly conditioned horse can become a poor fit three months later. Bodies change. Saddles do not get the memo.

7. Shockwave therapy

Shockwave may be used by some veterinarians as an adjunct for sacroiliac region pain or surrounding soft tissue pain. It should be seen as supportive rather than curative.

It does not replace diagnosis, rehabilitation, or treatment of concurrent lameness.

How Long Does Recovery Take?

Recovery depends on the cause, chronicity, severity, and whether there are concurrent problems.

Broadly:

• Mild, recent soreness may improve over weeks with correct management
• Moderate cases often need 6 to 12 weeks or more of structured rehabilitation
• Chronic cases may require several months of management
• Horses with multiple orthopaedic problems have a more guarded prognosis
• Returning too quickly to canter, jumping, or collection commonly causes setbacks

One long-term outcome study of 84 conservatively managed horses with sacroiliac joint region pain found that only 16.7% returned to full work, 32.1% returned to a lower level of work, 34.5% were retired, and 16.7% were euthanised shortly after diagnosis. The authors concluded that chronic sacroiliac joint region pain carries a poor prognosis for returning to full athletic function and a guarded prognosis for returning to some lower level of athletic activity. (EquiManagement)

That sounds heavy, but it is useful context.

It does not mean every horse with sacroiliac pain is doomed.

It means chronic, established sacroiliac region pain should be taken seriously, especially when it exists alongside other orthopaedic problems.

What Should You Do Right Now?

If the signs are mild and recent

Reduce hard work for a few days.

Avoid:

• Jumping
• Deep footing
• Hard hill work
• Tight circles
• Collection
• Repeated canter transitions
• Pushing through resistance

Check:

• Saddle fit
• Hoof balance
• Workload change
• Recent slips or falls
• Whether the issue improves or returns immediately

If signs persist beyond 1 to 2 weeks, book a veterinary assessment.

If the horse is resisting canter, bucking, or losing performance

Do not label it behavioural too quickly.

Book a lameness and ridden assessment. The combination of poor canter, reduced hindlimb impulsion, trunk stiffness, and resistance under saddle is exactly where sacroiliac region pain can hide. (EquiManagement)

If the horse is clearly lame

Do not start with sacroiliac injections.

Start with a proper lameness workup. Limb pain is common and may be contributing to the back or sacroiliac signs. Merck describes diagnostic blocks as an important part of localising lameness when physical examination alone does not identify the source. (Merck Veterinary Manual)

If the horse has sudden severe signs

Do not ride.

Call a veterinarian urgently if there is trauma, severe lameness, ataxia, collapse, severe pain, fever, dark urine, or inability to stand.

Common Mistakes With Sacroiliac Pain

Mistake 1: Diagnosing it from one sign

Tail to one side, bunny hopping, or poor canter can suggest sacroiliac pain, but none of these confirms it.

Mistake 2: Ignoring other lameness sources

Sacroiliac region pain commonly occurs with other orthopaedic problems. In one study, proximal suspensory and stifle pain were frequently found alongside sacroiliac region pain. (PLOS)

Mistake 3: Relying on imaging alone

Negative imaging does not rule out sacroiliac region pain. Ultrasound and scintigraphy can add information, but they do not perfectly confirm or exclude the diagnosis. (EquiManagement)

Mistake 4: Injecting without rehabilitation

Pain relief without strengthening often leads to temporary improvement followed by relapse.

Mistake 5: Returning to canter too early

Canter is often where sacroiliac horses struggle most. If the horse is rushed back into canter, collection, or jumping before strength returns, the problem can flare again.

Mistake 6: Blaming the horse’s attitude

Bucking, refusing canter, drifting, or resisting collection can be pain behaviour. Training matters, but pain should be ruled out before labelling the horse difficult.

Mistake 7: Forgetting the rider and saddle

A crooked rider, poor saddle fit, slipping saddle, or asymmetric workload can keep reloading the same sore region.

How To Reduce the Risk of Sacroiliac Pain Coming Back

You cannot prevent every case, especially after trauma or high-level athletic strain. But you can reduce recurrence risk.

Practical prevention includes:

• Keep farrier care consistent
• Maintain good hindlimb and foot balance
• Build fitness gradually
• Avoid sudden jumps in workload
• Use varied terrain carefully
• Avoid repetitive deep footing
• Warm up properly before intense work
• Include straightness and core work
• Progress collection slowly
• Do not overdrill canter transitions
• Review saddle fit regularly
• Address rider asymmetry
• Treat hock, stifle, suspensory, foot, and back pain early
• Give the horse enough recovery between heavy sessions

The best prevention is not one exercise. It is good load management.

Horses get sore when the workload exceeds what their body is ready to stabilise.

Myth vs Reality

Myth	Reality
“A crooked tail means sacroiliac pain.”	It can be a clue, but it is not diagnostic.
“If imaging is normal, the sacroiliac region is fine.”	Negative ultrasound or scintigraphy does not rule it out.
“Sacroiliac pain is always the main problem.”	It often occurs with other lameness or back problems.
“An injection fixes it.”	Injections may reduce pain, but rehab and treating concurrent problems are essential.
“Rest alone is enough.”	Rest may reduce pain, but progressive strengthening is usually needed before return to work.
“Bucking in canter is behavioural.”	It can be behavioural, but pain should be ruled out first.

Frequently Asked Questions

Can sacroiliac pain in horses be cured?

Some horses with recent, mild sacroiliac region pain can return well with correct diagnosis, treatment, and rehabilitation. Chronic cases are more guarded, especially when other orthopaedic problems are present. Long-term outcome data suggests chronic sacroiliac region pain has a poor prognosis for return to full athletic function in many horses. (EquiManagement)

How do vets confirm sacroiliac pain?

Vets usually combine history, physical exam, ridden and lameness assessment, diagnostic analgesia, and imaging. Diagnostic analgesia can support the diagnosis, but it is not perfectly specific because the sacroiliac region sits close to other lumbosacral structures. (PLOS)

Can a saddle cause sacroiliac pain?

A poor saddle fit or slipping saddle can contribute to back pain, altered movement, muscle guarding, and uneven loading. It may not be the only cause, but saddle fit should be reviewed in horses with back, pelvic, or performance problems.

Should I keep riding a horse with suspected sacroiliac pain?

Do not push through worsening signs. If the horse is bucking, resisting canter, clearly lame, weak behind, or rapidly losing performance, stop hard work and arrange a veterinary assessment. Gentle work may be appropriate in some mild cases, but only once pain and safety have been considered.

What conditions are most commonly confused with sacroiliac pain?

Common lookalikes include hock pain, stifle pain, proximal suspensory desmitis, foot pain, kissing spines, thoracolumbar pain, saddle fit problems, rider asymmetry, neurologic disease, and poor conditioning.

The Bottom Line

Sacroiliac pain in horses is real, but it is not a diagnosis to make from a single gait sign.

The signs that matter most are reduced hindlimb impulsion, trunk stiffness, canter problems, resistance under saddle, poor performance, muscle asymmetry, and signs that worsen when the horse is asked to push, sit, collect, jump, or canter.

But the real clinical message is this:

Sacroiliac region pain is often part of a bigger lameness picture.

The best outcome comes from diagnosing the whole horse, not just treating the sore-looking area. That means assessing the limbs, back, saddle, rider, workload, fitness, and sacroiliac region together.

If your horse is mildly stiff but improving, monitor and adjust workload.

If the horse is repeatedly resisting canter, losing impulsion, bucking, drifting, or feeling weak behind, organise a veterinary workup.

If the horse is suddenly severely lame, ataxic, unable to stand, painful after trauma, or deteriorating quickly, treat it as urgent.

Sacroiliac pain is frustrating because it hides. A proper diagnosis brings it out into the open.

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If you are unsure whether your horse’s poor canter, hindlimb weakness, back pain, bucking, or performance change could be sacroiliac pain or another lameness problem, ASK A VET™ can help you organise the signs, track the timeline, and decide when veterinary care should not wait.