Written by Dr Andy Richardson, Veterinary Director - BVSc CertAVP(ESM) MRCVS & Kate Hore, Head Nutritionist. RNutr, BETA ENFAR, R.Anim.Technol (Cert)

Sand colic in horses: causes, symptoms & management

For the past few years, the UK has seen record breaking temperatures in the summer. These hot and dry conditions are now commonplace across the country with many fields looking more like sand pits than pasture.

Horses that graze on sparse grass in dry fields have a real risk of ingesting sand, and and excess sand in the gut can lead to sand colic.

In this blog, we explain what sand colic is and what signs to watch for in your horse.

What is Sand Colic?

Sand colic occurs when your horse has ingested relatively small amounts of sand over time, usually whilst grazing. The excess sand accumulates in the large colon and caecum, causing abrasive damage to the gut lining, and ultimately a partial or complete blockage.

While horses ingesting sands can occur on any type of soil, the risk is increased for those on sandy soils and a decreased for those on clay soils. Bare and poorly maintained pastures also increase the risk, as do certain feeding practices, such as feeding from the floor.

Signs of sand in your horse's gut

• Sand in the droppings
• Loose droppings
• Poor appetite and weight loss
• Lethargy
• Mild, recurring colic episodes

If you suspect your horse may have sand colic, contact your equine vet for professional guidance.

Sand Accumulation Test

If your horse has a history of sand colic, is on sandy or overgrazed paddocks, or if they are being fed whilst loose in a ménage, then monitoring through doing a sand accumulation test may be advised. You’ll need a large, clear plastic bag or large glove.

1. Take a few balls of manure from the top of a pile – ensuring it is not touching the ground.
2. Place in a large, clear glove or large plastic bag.
3. Add a litre of water and massage manure until it dissolves.
4. Hang the bag or glove up for 30 minutes, if using a bag, ensure one corner points down.
5. Presence of sand shows an accumulation.
6. Repeat over several days, as one clear test does not guarantee a sand-free gut.

This test provides an indication only and should not replace veterinary examination if colic is suspected.

How to Help Horses with Sand Colic

Sand colic is unpleasant enough for your horse, causing abdominal pain, diarrhoea, weight loss and poor performance, but can also cause a life-threating bowel obstruction in your horse.

If you think your horse has sand colic, contact your vet as soon as possible for futhur advice.

Here are some of the other ways you can help support your horse with sand colic, and how to prevent your horse from ingesting too much sand.

Nutritional Management: Psyllium & Probiotics

Commonly recommended by both vets and nutritionists, psyllium is a useful natural plant to help clear accumulation. Psyllium is a herb high in naturally soluble fibers that form a mucilaginous gel when ingested. This gel is understood to bind sand within the digestive tract, supporting its passage through the digestive tract. Think of it as almost like a yard broom for the gut.

Additionally, this unique herbal action helps to support gut motility, encouraging the horse’s digestive system to maintain its natural contractions, rather than letting sand settle. The mucilaginous nature of psyllium may also help with any irritation caused by accumulated sand.

Whilst psyllium alone is often recommended, research supports feeding psyllium in a complex including probiotics and prebiotics to maximise support of the hindgut microbiome.*

Low level psyllium for horses can be fed daily for general gut health, either alone or as part of a gut health complex. For sand-clearing it is fed at higher rates in a short-course, typically for one week out of every month, over the dry grazing season.

Reducing the Risk

Good nutritional management is only part of the approach. Prevention is just as essential to protect your horse from sand colic. Here are some top tips for preventing your horse ingesting too much sand:

• Feed forage in haynets or feeders, not directly on sandy soil
• Use rubber mats under nets to capture loose hay
• Use multiple feeders around the field to ensure all have easy access (being lower in the hierarchy can increase the risk)
• Feed a high-fibre diet to encourage natural gut motility
• Offer additional forage if grazing is limited
• Regular sand-clearing, through monthly courses of a psyllium-based supplement
• Rotate paddocks where possible to avoid over-grazing