The term ‘colic’ simply means abdominal pain. There are multiple causes, including sand impaction or sand enteropathy which is of particular significance given our coastal location.
Clinical Findings
Sand colic may manifest in one of two clinical ways: diarrhoea and/or impaction.
Diarrhoea is caused through mucosal inflammation caused by constant abrasion by the sand within the lumen of the bowel. This constant irritation and abrasion results in a reduction of the absorptive surface of the bowel, thus causing chronic diarrhoea and weight loss. These horses are often ‘colicky’ intermittently. Notably, the colic symptoms are often occurring when the horse is producing manure of a normal consistency. This is significant in regard to diagnosis as with other causes of diarrhoea, the horse is colicky at/around the time of diarrhoea production.
Colic symptoms associated with sand impaction colic is typically secondary to tension on the mesentery (tissue that connects abdominal contents to body wall), due to the weight of the sand within the bowel. In chronic cases, horses may show low grade colic symptoms intermittently, including; standing stretched out, lying on their side or flank watching. Symptoms of colic can appear more acute/severe in cases, where the colon becomes obstructed, torsed or displaced because of the chronic sand accumulation.
Diagnosis
There are a number of ways our vets may diagnose sand colic; however, the simplest way is to perform a faecal sand sediment test. This involves taking 3-4 faecal balls and soaking them in water within a rectal palpation glove. Due to the weight of sand, it will settle in the fingers of the glove, while the ingesta and water will sit on top. More than 1 teaspoon of sand per 4 faecal balls is considered evidence of sand accumulation.
Additionally, rectal palpation or diagnostic imaging (ultrasound or xray) can be used to diagnose sand accumulation.
Treatment
The aim for treating sand colic involves managing pain and inflammation and lubricating and disrupting the obstructing mass. Medical management of sand colic typically involves administering pain relief in the form of flunixin intravenously and dosing the patient with psyllium husk orally or nasogastrically. Psyllium has the ability to penetrate, hydrate and disrupt sand impactions, thereby allowing the sand to be passed in the faeces. If psyllium is ineffective in resolving the impaction, magnesium sulfate in combination with mineral oil administered nasogastrically may be effective.
Surgical Treatment
In patients that are refractory to medical management or those that are acutely, uncontrollably painful, surgical intervention may be required physically remove the sand.
Prevention
