Difference between revisions of "Sand Impaction - Horse"
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===Description=== | ===Description=== | ||
| − | Sand impaction of the large colon is seen in horses with limited access to drinking water or those grazing bare pastures. Occasionally sand may be consumed | + | Sand impaction of the large colon is seen in horses with limited access to drinking water or those grazing bare pastures. Occasionally sand may be consumed when included with hay. The ingested sand may act as an inflammatory stimulus leading to a foreign body enteritis, commonly known as 'sand colic'. Alternatively the sand may accumulate and form a sediment within the right dorsal colon, pelvic flexure and transverse colon leading to an impaction. |
Sand impactions are particularly common in dry sandy regions of the world and are far less common in the UK and rest of Europe. Although all horses may be affected, indiscriminate feeders and young horses that may consume sand voluntarily are more commonly affected. Horses fed on low-roughage diets are more prone to developing the condition. | Sand impactions are particularly common in dry sandy regions of the world and are far less common in the UK and rest of Europe. Although all horses may be affected, indiscriminate feeders and young horses that may consume sand voluntarily are more commonly affected. Horses fed on low-roughage diets are more prone to developing the condition. | ||
Revision as of 14:34, 2 August 2010
Medical Treatment of Colic in Horses
Description
Sand impaction of the large colon is seen in horses with limited access to drinking water or those grazing bare pastures. Occasionally sand may be consumed when included with hay. The ingested sand may act as an inflammatory stimulus leading to a foreign body enteritis, commonly known as 'sand colic'. Alternatively the sand may accumulate and form a sediment within the right dorsal colon, pelvic flexure and transverse colon leading to an impaction.
Sand impactions are particularly common in dry sandy regions of the world and are far less common in the UK and rest of Europe. Although all horses may be affected, indiscriminate feeders and young horses that may consume sand voluntarily are more commonly affected. Horses fed on low-roughage diets are more prone to developing the condition.
Clinical signs
Ingestion of sand without impaction may lead to clinical signs pertaining to a physical colitis due its abrasive nature. These may include diarrhoea, If sufficient sand has been ingested to cause an impaction, the clinical signs are generally dependent on the anatomical site affected. Horses affected by a pelvic flexure impaction often present with signs of mild abdominal pain and generally respond well to conservative treatment. Impaction of the transverse colon is often associated with more severe abdominal pain due to the build up of gas in the the colon proximal to the obstruction.
Diagnosis
Affected horses may have a history of living in a sandy environment, grazing in dry weather or a reduction in water intake. Auscultation of the abdomen may reveal gritty-sounding 'rubs' heard as the sand moves through the colon. Definitive diagnosis of an impaction is made via rectal palpation or transrectal ultrasonography with identification of sand in the colon. In many cases however the impacted segment is located in the cranial gastrointestinal tract and therefore out of reach. Transrectal ultrasonography may assist in identifying the presence of sand.Sand also may be seen in the faeces by mixing faecal material with water in a plastic rectal examination sleeve and allowing the sand to fall to the bottom. If performed, abdominocentesis should be carried out with extreme caution in order to avoid inadvertent laceration of the sand-impacted colon.
Abdominal radiography may be useful in assessing the volume and location of sand impactions in foals, minature horses and small ponies.
Treatment
Bulk laxatives such as Psyllium are widely used to assist in the movement of sand. A mixture of Psyllium mucilloid and water is administered directly into the stomach via a nasogastric tube . Some authors however have described no benefical effects of Psyllium and adovate restriction to access to sand as the main component of treatment. This treament is continued for up to a week until all sand is fully removed from the colon.
If the impaction is large or non-responsive to medical treatment, surgery may be indicated.
Prevention of recurrence is important; horses should be fed from buckets to prevent further ingestion of sand. Water should be freely available and plentiful. Horses should not be allowed access to over-grazed pasture. High fibre diets such as hay are recommended.
Prognosis
For cases that are not resolved by conservative treatment, the prognosis is good if surgery is performed early. The overall mortalitiy rate for horses requiring surgery is reported to be 40%.
References
Hammock, P. D., Freeman, D. E., Baker, G. J. (1998) Failure of Psyllium Mucilloid to Facilitate the Evacuation of Sand from the Equine Large Intestine AAEP Proceedings 9 Vol. 44 pp 246-247
Mair, T. S., Divers, T. J., Ducharme, N. G. (2002) Manual of Equine Gastroenterology Elsevier Health Sciences
Robinson, N. E., Sprayberry, K. A. (2009) Current Therapy in Equine Medicine Elsevier Health Sciences
Rose, R. J., Hodgson D. R. (2000) Manual of Equine Practice Elsevier Health Sciences