Sand ingestion a silent killer

With the continuing drought and diminishing grazing, farmers are forced to supply their livestock and game with supplemental feeding. As the grazing deteriorates, animals are forced to graze down to ground level, which inadvertently leads to some sand ingestion. This can lead to secondary intestinal sand impaction.

Wildlife Vets Namibia had a few cases recently. Pica is when animals eat or nibble on something which does not have any (or hardly any) nutritional value. Examples of pica are the eating of bones (osteophagia), or eating soil (geophagia). This behaviour is likely associated with some nutritional deficits (e.g. phosphate deficiency or starvation).

Animals can, however, also ingest sand unintentionally when sand sticks to food (poor quality and/or sand contaminated hay) or where soil is ingested directly by eating grass from a sandy soil. Animals forced to eat a pasture all the way down to the grass’s roots, as under drought conditions, are also at risk.

Why is sand a problem?

Sand in relatively low quantity is not a big issue, it might be irritating to the intestinal mucosa, often causing diarrhoea. But when an animal ingests lots of sand, it will become a problem. Since sand is heavier than the normal intestinal content, it accumulates in the lower parts of stomach/intestine. This causes distension (swelling) and eventually impaction (blockage), thereby disrupting the normal peristalsis of the intestine.

Treatment

There are different opinions regarding the treatment and effectiveness thereof of in cases of sand impaction. In wild animals, the diagnosis will most likely only be made during an autopsy or based on suspicion. Effective treatment usually requires intensive 'hands-on' management, which is impractical in game, but may be considered in horses and cattle.

Treatment recommendations mentioned in the literature include: Repeated administrations of Equisyllium, a high-fibre laxative which is a popular choice in horses, with claims that the fibre swells up in the stomach, collects the sand and moves it through the digestive tract to be passed in the manure. However, studies conducted at the universities of Illinois and Florida concluded that psyllium had no apparent effect on sand removal from a horse’s large intestine.

A feeding trial at the University of Florida concluded that feeding large amounts of hay (2.5% of body weight) uniformly produced the largest sand output, even when compared to the combination of high a fibre diet with additional Equisyllium.

Other studies found that feeding wheat bran and dosing with mineral oil to remove sand also proved ineffective. In some cases, surgery is needed.

Well-balanced diet

As always, prevention is better than cure. First of all, make sure animals get a well-balanced diet, which will reduce the inclination to nibble on dirt, bones, etc.

Wherever possible, avoid overgrazing to prevent animals eating too close to the ground, which is especially important in sandy areas. If you have to give supplemental feeding, avoid feeding directly from the ground since this will increase sand contamination of food and sand ingestion.

Feed off the ground as much as possible:

o Feed in hay stacks and use a rubber mat under feeding areas to catch the feed that inevitably falls on the ground. This also minimises wastage of expensive food.

o Feed on rubber covered (conveyor belting) ground away from sandy areas. Please note that these do get very hot in the sun, thus place in shady areas.

o Feed on natural rock surfaces (if available) or make concrete slabs.

o Provide feeding bowls.

Provide multiple feeding spots spread over a wide area to ensure all animals get a chance to eat.

A high fibre intake (ideally in unlimited quantity on farms with sand ingestion problems) is a high priority, since the high fibre content will assist with sand removal from the gut.

Since dehydration will exacerbate intestinal impaction, always provide plenty of fresh water.

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