Some horses suffer from recurrent colic, loose manure, prolonged diarrhoea, abdominal sensitivity, or varying degrees of reduced performance. Colic may present as either constipation or gas. Horses with sand in the intestines often show changes in manure consistency, and water separating from manure may indicate sand accumulation in the large intestine.
Other symptoms may include a poor coat or urinary difficulties. Horses suffering from such issues should undergo diagnostic investigations to rule out underlying causes. One of the first examinations often performed is sand imaging. At home, sand intake can be assessed with the so-called glove test, where a manure ball is placed into a rubber glove, water is added, and the glove is observed to see whether sand settles at the bottom. This test only indicates that the horse is ingesting sand and that it passes through the digestive tract. It does not confirm whether sand has accumulated in the intestines. A veterinarian may detect intestinal sand by auscultating gut sounds. In cases of sand accumulation, the normal gut sounds may be replaced by a characteristic “sand noise.” However, the only way to be completely certain is to take radiographs of the horse’s abdominal cavity.
Based on current understanding, sand ingestion appears to be most common in leisure horses and particularly in Finnhorses. The exact cause of sand eating is not known. It seems that some horses eat sand out of boredom, while others appear to like its taste and continue eating it despite grazing muzzles or enrichment. It has also been suggested that horses may ingest soil in an attempt to compensate for mineral deficiencies, particularly zinc and copper. These horses are often seen licking clay soil or digging up roots and other materials. Horses may also accumulate sand by eating hay from the ground. Greedy horses that eat their hay down to the very last stem are particularly at risk of “vacuuming” sand along with their forage. Grazing on sparse pasture and pulling grass up by the roots can also lead to soil ingestion.
Some horses have slower gut motility, which means that excess material is not cleared effectively during normal digestion. Sand accumulation at the bottom of the intestine can create a vicious cycle. The weight of the sand interferes with normal intestinal movement, leading to further accumulation. To the best of current knowledge, no scientific studies have confirmed this, but some owners believe that sand eating may also be associated with gastrointestinal discomfort or pain, such as gastric ulcers, long intervals between feedings, or stress. It has been suggested that horses may eat sand to relieve gastric acid irritation during long feeding gaps or ulcer pain. However, there is no scientific evidence to support this theory.
What can help?
The most important step is to prevent further sand ingestion. For some horses, this may require the use of a grazing muzzle. Unfortunately, some horses have such a strong craving for sand that they manage to ingest it even through a muzzle. Greedy horses may benefit from hay nets or feeding from raised surfaces, which reduces the intake of soil along with hay. Some horses improve when the paddock base is modified, but this often requires extensive groundwork and underlay materials to prevent the horse from digging sand up again. For some horses, moving to pasture may be sufficient, as manure becomes looser and moves more easily through the gut. If sand ingestion is related to mineral deficiency, some horses have benefited from products containing bentonite clay. Bentonite is a mineral-rich supplement that may also help stabilise gut pH.
Gastro Clay B, 27,90 €
Psyllium seeds from 33,90 €
Sand accumulations in the horse’s intestines can be addressed with various products, such as psyllium husk powder, psyllium seeds, chia seeds, or chia meal. The effectiveness of different products varies between horses, as does palatability. Some owners of sand-eating horses administer preventive “sand-clearing courses” a few times per year. When feeding psyllium, it should be remembered that its laxative effect decreases with long-term use, as gut bacteria begin to utilise it as a nutrient. This is believed to occur after approximately one month of continuous feeding. There is no restriction on long-term chia feeding, and it also provides the horse with valuable nutrients.
A veterinarian can remove sand by administering nasogastric tubing. Treating large sand accumulations is not without risk, and some horses may develop colic when the sand begins to move. In certain acute colic cases, sand is removed surgically. Large and heavy accumulations can damage the intestinal wall, potentially leading to rupture in the worst cases. For this reason, sand colic is usually treated medically unless pain or displacement of the intestine necessitates surgery.
Below are radiographs taken of our customer’s horse before and after chia feeding. In the top image, three sand accumulations are visible on the left.
Sources:
- www.hyvinkaanhevossairaala.fi
- www.hevostietokeskus.fi
- www.heppalaakari.fi
- Faculty of Veterinary Medicine, Department of Clinical Equine and Small Animal Medicine
- Hevoset ja Ratsastus magazine, article by Riitta Jalonen
