may be out of reach. Cecal and large colon gas disten- tion is inevitably present. Horses with this condition may have small amounts of diarrhea and clinical signs of endotoxemia. Abdominal paracentesis should be conducted cau- tiously since the sand-impacted colon can be inadver- tently lacerated. An abdominal paracentesis should not be performed in horses that clearly require surgical intervention or in horses in which the procedure may be of low diagnostic value. Sand present within an enterocentesis is pathognomonic for the disease. Auscultation of the ventral abdomen of horses with sand impaction may reveal 'friction-like' rub sounds compatible with sand borborygmi. DIAGNOSIS Sand impaction can be difficult to differentiate from feed impaction, and tests for fecal sand do not correlate well with the presence of sand in the colon. History or observation of sand in the feces only indicates exposure to sand. Sand may be detected during transrectal palpa- tion or it may be found on the rectal sleeve. Dissolving feces in water and observing for sand in the bottom of a bucket or on a rectal sleeve may provide evidence of the possibility of sand impaction. Although small amounts of sand are frequently found in feces and do not neces- sarily reflect sand impaction, large amounts of sand are more indicative of sand accumulation. Comparison of the normal discharge of sand in normal horses from that of the diseased horse may assist in the diagnosis of sand impaction. Ultrasonog~aphic examination of the ventral abdomen along the midline caudal to the xiphoid process with a &MHz ultrasound probe may reveal the presence of sand in the ventral colon, appearing as floating starburst spicules as the sand is suspended in the ingesta. Abdominal radiographs, if available, can aid in the diagnosis of sand impaction. TREATMENT Psyllium mucilloid (0.5-1.0 g/kg p.0. q. 6 2 4 h) has been implemented to lubricate the gastrointestinal tract and assist in the movement of sand out of the body. A solution of psyllium mucilloid and 4-8 liters of water must be pumped rapidly into the stomach via a nasogastric tube before the psyllium mucilloid forms a gel. The treatment is maintained for several days to a week depending on the severity of the case. The feces should be monitored for the rate of expulsion of the sand. Psyllium, however, had no effect in hastening sand evacuation from the large intestine in a controlled experimental study in six normal ponies. Further studies on the effect of psyllium in the diseased colon are needed. Intravenous fluid therapy may be necessary in horses that do not respond to initial treatment with analgesics and laxatives. Intravenous fluid administration may increase the water content of the impacted ingesta in horses by raising the capillary hydrostatic pressure and decreasing plasma protein concentration. The recom- mended administration rate for intravenous fluids is.
You've reached the end of your free preview.
Want to read all 3 pages?
- Fall '19
- Large intestine, Colon, Intravenous therapy, colic, Horse colic