Equis ISSN 2398-2977

Gastrointestinal: sand colic

Synonym(s): Sand enteropathy

Contributor(s): Debbie Archer, Peter Rakestraw

Introduction

  • Sand colic is a relatively common type of colic in areas with sandy soil, and at times of year when the grazing is poor.
  • Cause: ingestion of sandy soil.
  • Signs: weight loss, diarrhea and colic.
  • Diagnosis: based on presence of earth/sand in dung.
  • Treatment: includes the use of bulk laxatives, in very severe cases surgery may be necessary.
  • Prognosis: is good in mild cases that are recognized promptly.

Pathogenesis

Etiology

  • Ingestion of sand/earth causes this condition.
  • Horses can easily ingest earth if they are provided with insufficient nutrition, are on poor pasture, and are trying to graze very short grass.
  • Some horses will preferentially graze even if sufficient hay is provided and are therefore likely to be affected when on short pasture.
  • Horses fed hay on the ground when turned out on bare pasture or in sand schools can easily ingest sand.
  • Some horses will try to eat earth, this can be a sign of an underlying disease such as liver disease or may indicate a mineral deficiency.

Predisposing factors

General
  • Turnout in bare sandy paddocks or schools.
  • Light sandy soil or grazing grass covered by silt after flooding.
  • Hunger, insufficient provision of food.
  • Drinking from shallow muddy pools. 
  • Greed.
  • Lack of salt/minerals indicated.

Pathophysiology

  • Horse ingests sand during feeding or grazing.
  • Small quantities of sand will pass through the gastrointestinal tract; diarrhea may be seen due to the irritant effects of the sand on the colonic mucosa.
  • In larger amounts sand tends to accumulate in the large colon. It is rare for sand to accumulate in the stomach, small intestine or cecum. The large colon is a fermentative region with reduced flow of ingesta allowing sand to settle.  
  • When this accumulation causes a blockage, impaction of sand results in colic due to stretching of the bowel wall and distention by ingesta and gas proximal to the site.
  • Volvulus of the colon may be initiated by gravity dependent rotation of the affected segment, lighter gass filled colon proximal to the site of impaction rising relative to the heavier portion of obstructed colon.
  • Sand in the intestines causes irritation of the mucosal surfaces with consequent inflammation.
  • Inflammation causes increased permeability of the gut wall, with consequent loss of solutes and water into the gut lumen.
  • Mucosal loss results in absorption or endotoxin resulting in endotoxemia   Endotoxemia: overview  .
  • Diarrhea results.
  • Build up of sand can cause obstructions, and can even predispose to volvulus. Necrosis of the bowel wall can develop at the site.
  • Impactions may occur at more than one site.
  • Common sites are pelvic flexure, right dorsal colon, left dorsal colon and transverse colon.

Diagnosis

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Treatment

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Prevention

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Outcomes

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Korolainen R, Kaikkonen R & Ruohoniemi M (2003) Ultrasonography in monitoring the resolution of intestinal sand accumulations in the horse. Equine Vet Educ (6), 423-430 VetMedResource.
  • Ruohoniemi M, Kaikkonen R, Raekallio M & Luukkanen L (2001) Abdominal radiography in monitoring the resolution of sand accumulations from the large colon of horses treated medically. Equine Vet J 33 (1), 59-64 PubMed.
  • Hillyer M H & Mair T S (1997) Recurrent colic in the mature horse - a retrospective review of 58 cases. Equine Vet J 29 (6) 421-424 PubMed.
  • Ragle C A, Meagher D M, Lacroix C A & Honnas C M (1989) Surgical treatment of sand colic; results in 40 horses. Vet Surg 18 (1), 48-51 PubMed.
  • Specht T E & Colahan P T (1988) Surgical treatment of sand colic in equids: 48 cases (1978-1985). JAVMA 193 (12), 1560-1564 PubMed.


ADDED