Depth and distribution of colonic sand accumulation in a desert population of horses and its association with diagnosis of sand colic.

OBJECTIVE: To describe patient and management characteristics associated with radiographic sand accumulation in a desert population of horses, as well as identify factors independently associated with a diagnosis of sand colic and need for surgical intervention. METHODS: Horses were prospectively allocated into 3 groups: control horses, horses with sand colic, and horses with non-sand-associated colic. Signalment, radiographs, and management outcomes were compared between groups. RESULTS: Median depth of sand was significantly greater in horses diagnosed with sand colic compared to other groups (112.16 vs 10.5 vs 12.0 mm). Increasing sand depth was associated with increased odds of having sand colic. Younger horses were more likely to be diagnosed with sand colic (2 vs 4.9 years); however, surgical intervention was more likely in older horses (2.6 vs 1.3 years). CONCLUSIONS: Horses diagnosed with sand colic exhibited greater sand depth compared to those with non-sand colic or controls. For every millimeter of sand present, horses had a 2% increase in the odds of being diagnosed with sand colic. Factors independently associated with a diagnosis of sand colic were a lower body weight, presence of cranial sand on radiographs, and increasing sand depth. CLINICAL RELEVANCE: The OR of a diagnosis of sand colic increases by 2% with every millimeter of measured sand depth. Additionally, greater depths of sand were not associated with increased risk of surgical management. This data helps clinicians determine the relevance of sand identified radiographically in horses presenting for colic.