Sand Impaction in a Horse

A six year old gelding presented for recurrent low grade fever and intermittent diarrhea. At the time of the initial exam the gelding was alert and showing no signs of discomfort. Vitals were normal and body temperature was 100.5 degrees.  A blood sample was collected for complete blood count (CBC) analysis and a rectal exam was performed. A large, firm structure was palpated along the left flank of the horse which was consistent with an impaction of the "pelvic flexure".  The fecal material removed from the rectum was partially formed and had a grainy feel to it. Several hand fulls of manure were placed in a rectal sleeve and the sleeve was filled with water (Figure 1).  A significant amount of sand was identified in the sleeve filled with water!

Figure 1

 The gelding was treated aggressively with water and mineral oil via a naso-gastric tube however; his condition worsened and he was referred to a surgical facility. Despite knowing that the gelding had a pelvic flexure impaction which is usually managed medically, the gelding was taken to surgery due to refractory pain. Abdominal exploration revealed an extremely large, firm impaction of the left colon which "bottle necked" at the pelvic flexure (blue arrow in Figure 2).  Discovery of such an impaction during surgery typically results in making a small opening in the colon wall and resolving the impaction. However, a small tear was discovered along the edge of the impaction which had resulted in fecal contamination of the abdomen. Prognosis was poor and the owners opted for humane euthanasia.

Figure 2

This case of sand impaction in a horse is sadly NOT uncommon in the state of Florida! The accumulation of sand within the colon of a horse is typically a result of poor pasture conditions and can develop very quickly. There are several "hair-pin" turns within the large colon of horses which create ideal conditions for the accumulation of sand and other debris. The pelvic flexure is one of those "hair-pin" turns and is one of the most common locations for colon impactions in horses. Unfortunately, once the sand impaction develops it is very difficult to resolve by providing oral medication such as psyllium (Figure 3)  and mineral oil (Figure 4).

Figure 3

Figure 4

The clinical indicators of sand accumulation in horses include intermittent diarrhea, low white blood cell count, fever and plus/minus colic. The sand is abrasive to the lining of the colon which results in diarrhea and sequestration of white blood cells in the colon wall. Horses with sand accumulation within their colons often have a week or month-long history of diarrhea! This is the time to treat the horse with sand clearing products. Once the horse becomes completely obstructed, surgery may be the only option to resolve the impaction. There are several products available to treat horses on a monthly basis as "sand clearing" products however once sand has accumulated within the colon, these products are not effective. They are more effective if used as products to prevent sand accumulation in combination with good pasture management! This condition is treatable but MUST be addressed when clinical signs first develop!!