Sand Colic in Horses: How to Remove and Prevent Sand Accumulation

By Dr Duncan Houston

Sand colic is one of those problems that can creep up quietly.

A horse may swallow tiny amounts of sand while eating hay from the ground, grazing very short pasture, or picking feed from sandy soil. One mouthful is not usually the issue. The problem is repetition. Over time, sand can settle in the large colon, irritate the gut lining, slow normal movement, and contribute to diarrhea, weight loss, recurrent colic, or impaction.

The important point is this: sand colic is not just a desert problem. It can happen anywhere horses eat from sandy, dusty, bare, or overgrazed ground.

Quick Answer

Sand can accumulate in a horse’s large colon after repeated ingestion from sandy soil, overgrazed pasture, or feed placed on the ground. Mild cases may cause loose manure, poor appetite, weight loss, or recurrent mild colic, while severe cases can cause obstruction, gut distension, and emergency colic signs. The best treatment depends on how much sand is present and how sick the horse is. Research supports veterinary-administered treatment using psyllium with magnesium sulfate, often given by nasogastric tube, while prevention depends mainly on reducing sand intake through better feeding management. (ScienceDirect)

What Is Sand Colic?

Sand colic refers to abdominal pain or digestive disease caused by sand accumulation in the gastrointestinal tract, usually the large colon.

The term “sand colic” is commonly used, but the broader veterinary term is sand enteropathy. That means digestive tract disease linked to sand. It may or may not involve obvious colic at the start.

Sand can cause problems by:

• Irritating the lining of the colon

• Slowing gut movement

• Contributing to diarrhea

• Increasing the risk of impaction

• Adding weight and drag to the colon

• Causing recurrent mild colic

• Triggering severe colic if obstruction or gas distension develops

UC Davis notes that horses in sandy-soil regions can accumulate sand after grazing or eating from the ground, and this can lead to gastrointestinal obstruction, intestinal irritation, altered gut motility, weight loss, diarrhea, and overt colic.

In practice, sand problems are easy to underestimate because the signs can start subtly. The horse does not always begin with dramatic rolling and sweating. Sometimes the first clue is simply loose manure, dullness, or a horse that keeps having “minor” colic episodes.

Why Does Sand Accumulate in a Horse’s Gut?

Horses usually ingest sand accidentally.

Common risk factors include:

University of Minnesota Extension specifically advises avoiding hay feeding on the ground in sandy areas and recommends feed tubs, hay racks, rubber mats, or catch pans to reduce the amount of sand eaten. (University of Minnesota Extension)

The mistake I see most often is thinking, “There is only a little sand there.” That may be true today. But if the horse eats from that same patch every day, small amounts can become a large colon problem.

What Signs Suggest Sand Accumulation?

Sand accumulation can look like many other digestive problems. Some horses show obvious colic. Others show vague, repeated, low-grade signs.

Possible signs include:

Sand colic should be on the list when a horse has repeated mild colic, especially if they live on sandy soil or are fed from the ground.

But sand is not the only possible cause. That is why proper diagnosis matters.

What Else Can Look Like Sand Colic?

A horse with diarrhea, weight loss, poor appetite, or recurrent colic signs may have sand accumulation, but there are other important possibilities.

Common rule-outs include:

• Gas colic

• Feed impaction

• Large colon displacement

• Parasites

• Dental disease causing poor chewing

• Hindgut inflammation

• Salmonella or other infectious diarrhea

• Gastric ulcers

• Enteroliths

• Liver or kidney disease

• Poor-quality forage

• Sudden diet change

• Toxic plants

• Pain from another body system

The real concern is not just whether sand is present. Some horses can pass small amounts of sand without it being the main problem. The clinical question is whether the sand burden is large enough to explain the signs and whether the horse is developing obstruction, gut distension, dehydration, or systemic illness.

How Do Vets Diagnose Sand in the Gut?

There are several ways to look for sand, but they are not equally reliable.

Fecal sand sediment test

This is the simple “manure in a glove or bag with water” test. Sand may settle at the bottom after the manure breaks down.

It can be useful as a rough screening tool, but it is not definitive. A horse can have sand in the colon and not shed much sand in that particular manure sample.

Listening for sand sounds

Some vets may hear characteristic gritty or “waves on a beach” sounds when listening along the lower abdomen, but this is not reliable enough on its own.

Ultrasound

Ultrasound can help in some field situations, especially as a screening tool. A 2022 review notes that ultrasound can be useful under field conditions, particularly for ruling out sand accumulation, but is more limited in acute disease assessment. (Research Portal)

Radiographs

Abdominal radiographs are often the most useful way to confirm and quantify sand accumulation, especially when the horse is small enough and equipment is available.

The same 2022 review states that radiography remains the reference standard for diagnosis of sand accumulation in acute disease. (Research Portal)

UC Davis also highlighted that radiographs help confirm sand in the gut and estimate how much has accumulated, while fecal sedimentation and abdominal sounds may be much less reliable.

In plain English: manure tests can raise suspicion, but x-rays are often what turn suspicion into a plan.

How Worried Should You Be?

Sand accumulation ranges from low-grade and manageable to life-threatening.

The key decision point is whether the horse is comfortable, eating, hydrated, and passing manure. If pain is persistent, worsening, or repeated, do not wait.

When Is This an Emergency?

Call a vet urgently if your horse has:

• Repeated rolling or violent pain

• Sweating without exercise

• Fast breathing or fast heart rate

• Pale, dark red, purple, or muddy gums

• No manure output

• Severe diarrhea

• Signs of dehydration

• A swollen or tight abdomen

• Depression or weakness

• Colic signs that do not improve quickly

• Pain that returns after initial treatment

• Recurrent colic over days or weeks

University of Minnesota Extension advises calling a veterinarian when colic is severe, does not improve with walking, the duration is unknown, the horse has not been observed for several hours, or vital signs are abnormal. (University of Minnesota Extension)

If your horse is thrashing, do not try to heroically drag them around the yard. Keep yourself safe, move the horse only if you can do so safely, and get veterinary help.

What Removes Sand From a Horse’s Gut?

This depends on the case.

A mildly affected horse with a small sand burden may be managed differently from a horse with a large radiographic accumulation, dehydration, gas distension, or active colic.

Psyllium

Psyllium is a soluble fiber that forms a gel-like material when mixed with water. It is commonly used in horses at risk of sand accumulation.

However, the evidence is more nuanced than many product labels suggest. A 2022 review states that current evidence does not support feeding psyllium alone for removal of established sand accumulation. Instead, studies support veterinary administration of psyllium combined with magnesium sulfate by nasogastric tube. (Research Portal)

So psyllium may have a role, but it should not be treated as a magic sand vacuum.

Magnesium sulfate

Magnesium sulfate, also known as Epsom salts, acts as an osmotic cathartic. In simple terms, it draws water into the intestinal contents and can help move material through the gut.

It is not something to casually dose in large amounts at home. Excessive magnesium sulfate can cause serious toxicity. MSD Veterinary Manual notes that horses receiving excessive oral magnesium sulfate may develop signs such as sweating, muscle weakness, rapid heart rate, rapid breathing, recumbency, and, at very high magnesium levels, cardiac arrest. (MSD Veterinary Manual)

Psyllium plus magnesium sulfate

This is where the evidence is strongest.

A 2014 prospective randomized study compared psyllium alone, magnesium sulfate alone, and the combination in horses with large colon sand accumulations. Nine of 12 horses treated with the combination cleared the sand within four days, compared with three of 12 treated with psyllium alone and two of 10 treated with magnesium sulfate alone. (ScienceDirect)

A 2018 prospective study also found that horses treated with psyllium and magnesium sulfate by nasogastric tube cleared sand more often than untreated control horses, with 75% of treated horses resolving over four days compared with 20% spontaneous resolution in controls. (ScienceDirect)

A 2025 Australian Veterinary Journal case series reported that treatment with psyllium, magnesium sulfate, and paraffin oil by nasogastric tube cleared more than 75% of sand area in 81% of equids over a median of four days, although Miniature Ponies had a lower success rate and complications occurred in 30% of cases, usually mild or self-limiting. (Murdoch Research Portal)

The practical message is clear: for established sand accumulation, the best-supported protocols are veterinary treatments, not casual home dosing.

Can You Use Psyllium Monthly for Prevention?

Many horse owners in sandy regions use psyllium periodically, often for several days each month. This is common, and some vets may recommend it for high-risk horses.

But it should be kept in perspective.

Psyllium is not a replacement for preventing sand intake. If the horse keeps eating hay from sandy ground, a monthly psyllium cycle is a bandage on a management problem.

The priority order should be:

1. Stop feeding from sandy ground.

2. Improve pasture cover and forage access.

3. Use feeders, tubs, mats, or hay nets.

4. Confirm whether sand is actually accumulating.

5. Use psyllium or veterinary treatment only when it fits the case.

Prevention starts with the ground, not the supplement tub.

What Should You Do Right Now If You Suspect Sand Colic?

1. Check whether your horse is actively colicky

Look for pawing, flank watching, rolling, sweating, lying down repeatedly, reduced manure, or refusing feed.

If signs are present, call your vet.

2. Remove feed while waiting for advice

If the horse is showing colic signs, remove hay and grain until you speak with your vet. Feed can add bulk to an impaired gut.

University of Minnesota Extension recommends removing feed while waiting for the veterinarian in a colic situation and notes that feed may add to an impaction. (University of Minnesota Extension)

3. Keep water available

Unless your vet tells you otherwise, clean water should remain available. Hydration supports gut movement and helps reduce impaction risk.

4. Do not give Epsom salts without your vet

This is important. Magnesium sulfate can be useful, but it can also be dangerous if used incorrectly, especially in horses with dehydration, kidney compromise, electrolyte abnormalities, severe gut disease, or dosing errors.

5. Move the horse only if safe

Gentle walking may help some horses and reduce rolling, but do not exhaust the horse. Do not put yourself under a thrashing horse’s feet. University of Minnesota Extension advises walking only if it helps the horse and never walking horse or handler to exhaustion. (University of Minnesota Extension)

6. Ask your vet whether imaging is needed

If sand colic is suspected, radiographs can be very helpful when available. They can confirm sand burden and help track response to treatment.

Common Mistakes Owners Make

Feeding hay directly on sandy ground

This is the classic mistake. Even clean hay becomes a sand delivery system if the horse is picking scraps from dirt.

Assuming diarrhea means “just hindgut upset”

Loose manure can have many causes, but in sandy areas, sand should be on the list.

Relying on a single manure sand test

A negative fecal sediment test does not rule out sand accumulation. Sand shedding varies.

Using psyllium as a cure-all

Psyllium may help in some prevention plans, but evidence does not support it as a reliable stand-alone treatment for established sand accumulation. (Research Portal)

Giving magnesium sulfate casually

Epsom salts are not harmless just because they sound old-fashioned. Excessive magnesium sulfate can cause serious toxicity. (MSD Veterinary Manual)

Waiting through repeated mild colic episodes

One mild colic may pass. Recurrent mild colic is a pattern. Patterns deserve investigation.

How To Prevent Sand Accumulation

Prevention is the strongest part of sand management.

Feed off the ground

Use:

• Hay nets

• Hay racks

• Rubber mats

• Feed tubs

• Large ground feeders

• Catch pans under racks

• Slow feeders placed on clean surfaces

Do not just put a hay net over sandy soil and call it fixed. Horses will still clean up dropped hay unless the area underneath is managed.

Use rubber mats in feeding areas

Mats help catch dropped hay and grain, but they need to be cleaned. A mat covered in sand is just expensive sand.

Avoid overgrazing

Short grass increases the chance of horses grazing close to the soil and pulling up dirt with roots. Rotational grazing, resting paddocks, and offering hay before pasture gets too short can reduce risk.

Provide enough forage

Hungry horses scavenge. Scavenging horses eat dirt.

A steady forage supply reduces the urge to pick through bare ground for scraps.

Move feeding sites

If one area becomes bare, dusty, and churned up, move the feeding location or improve the footing.

Manage herd dynamics

Make sure lower-ranking horses are not pushed into sandy corners or forced to eat dropped scraps after dominant horses finish.

Monitor high-risk horses

Horses with previous sand colic, recurrent loose manure, or repeated exposure to sandy soil may need periodic veterinary checks. In some cases, your vet may recommend radiographs to monitor sand burden.

Be extra cautious with Miniature Horses and ponies

Small equids can be more difficult to assess and may have different risk patterns. The 2025 case series found Miniature Ponies had a lower response rate to one medical sand-clearance protocol compared with other breeds. (Murdoch Research Portal)

Will a Horse With Sand Colic Be Okay?

Many horses do well when sand accumulation is recognized early and treated appropriately.

UC Davis reported that both medical and surgical management of horses with sand colic resulted in more than 94% survival to discharge in one review of 153 treated horses, although recurrence was common after medical treatment.

The prognosis becomes more guarded when there is severe pain, marked gas distension, dehydration, shock, poor response to medical treatment, intestinal displacement, or suspected obstruction. UC Davis noted that evidence of intestinal distension from gas accumulation may push decision-making toward surgery rather than medical treatment alone.

The earlier you identify the problem, the more options your vet has.

FAQs About Sand Colic in Horses

Can sand pass through a horse naturally?

Yes, small amounts of sand may pass in manure. The problem is when intake exceeds clearance and sand settles in the large colon. Some horses clear sand better than others, which is one reason exposure does not affect every horse the same way.

Does psyllium remove sand from horses?

Psyllium may help in some prevention or management plans, but evidence does not support feeding psyllium alone as a reliable treatment for established sand accumulation. Veterinary studies show stronger results when psyllium is combined with magnesium sulfate and given by nasogastric tube. (Research Portal)

Can I give my horse Epsom salts for sand?

Do not give magnesium sulfate for suspected sand colic unless your vet advises it. It can be useful, but excessive doses can cause dangerous hypermagnesemia, especially if the horse is dehydrated or medically compromised. (MSD Veterinary Manual)

How do I test manure for sand?

A simple screening test involves mixing manure with water in a clear bag or glove and letting heavier sand settle at the bottom. This can be useful, but it is not definitive. A negative test does not rule out sand in the colon.

What is the best way to prevent sand colic?

The best prevention is reducing sand intake. Feed hay and grain off sandy ground, use mats or feeders, avoid overgrazed pasture, provide enough forage, and monitor high-risk horses. University of Minnesota Extension recommends feed tubs or hay racks and rubber mats or catch pans in sandy areas. (University of Minnesota Extension)

Final Thoughts

Sand colic is a management problem before it becomes a medical problem.

Once a horse has a large sand accumulation, treatment may involve radiographs, fluids, pain relief, nasogastric tubing, psyllium, magnesium sulfate, paraffin oil, hospitalization, or even surgery. But the best time to deal with sand is before it becomes a heavy layer sitting in the colon.

The safest approach is simple: keep feed off sand, protect feeding areas, avoid overgrazing, provide enough forage, and investigate repeated mild colic or loose manure early.

Psyllium can have a place. Magnesium sulfate can have a place. But neither replaces clean feeding management, proper diagnosis, and veterinary judgement.

If your horse has recurrent colic signs, loose manure, weight loss, or known sand exposure and you are unsure how urgent it is, ASK A VET™ can help you decide the safest next step.