Diagnosis, management and prognosis of large colon impactions

Summary The majority of large colon feed impactions occur in the left ventral colon at the pelvic flexure. Sand and enterolith impactions most commonly occur in the left ventral colon at the pelvic flexure or in the right dorsal colon; however, sand can accumulate anywhere along the gastrointestinal tract. Enteral fluid therapy can, in most cases, supplement or even replace i.v. administration of fluids and it appears effective and safe to soften large colon contents and resolve simple large colon impactions. Surgical intervention is indicated when a concurrent displacement is suspected, as lengthy medical treatment of large colon impaction secondary to large colon displacements would not be indicated and may increase the risk of colonic rupture. Other indications for surgical intervention include uncontrollable pain, when cardiovascular parameters deteriorate, or when there is evidence of intestinal devitalisation. The prognosis for horses undergoing large colon enterotomy is dependent on the extent and type of impaction, but is generally excellent.