Equine Enterolithiasis

Accession # 114670Erica Fields, DVM

Toby Henderson 15 yo Appendix (no, really) gelding 9 day history of colic, unresponsive

to Banamine Large colon impaction palpated by

rDVM Presented to VTH – gas in cecum,

tension in cecal bands, no impaction palpated

An Appendix horse

Blikslager 2002

Enterolithiasis Pathophysiology

Typically struvite (ammonium magnesium phosphate)

Need a nidus for formation (often a silicon dioxide stone, nail, or piece of rope)

Possible causes/predisposing factors Increased magnesium diets Geographic distribution (in CA, 28% of

surgical colics have enteroliths!) Breeds (Arab, Morgan, Am. Saddlebred,

donkey)

Blikslager 2002

Enterolithiasis Common sites – right dorsal colon and

transverse colon Clinical signs

Intermittent colic in mature horses (>4 yo) Few rectal palpation abnormalities until large

enough to occlude colon and cause severe pain/distension

Treatment Generally, surgery is required – try to push

toward pelvic flexure enterotomy Prognosis – generally good (92% 1 year

survival for surgically treated). Rupture occurred in 15%.

Dorsal view of the colon

Cecum

Right ventral colon

Left ventral colon

Left dorsal colon Right dorsal

colon

Pelvic flexure

Transverse colon

Small colonhttp://www.vetmed.wsu.edu/Van308/_derived/

equine.htm_txt_lgcolon.gif

Blikslager 2002

Alternative DDx Colonic sand impaction

Common in horses on sandy soil Ground fed Sand accumulation usually in right

dorsal colon and pelvic flexure Clinical signs – diarrhea (irritates

mucosa), colonic impaction signs, sand in feces, “sand rubs”

Treatment – medical initially (Psyllium), may need surgery

Toby – Sand impaction

Sly – Enterolith

Reference Blikslager AT. Surgical disorders of

the large intestine. In Large Animal Internal Medicine, 3rd ed. 2002. pp 662-663.