Colics The Number One Horse Killer – part 2

Colics part 2

What causes it?

Colics can be broken down into three main categories; simple obstructions, strangulating obstructions, and non-strangulating infarction. Simple obstructions typically cover all types of impactions such as food impaction. Strangulating obstructions cover all the various forms of entrapments. And finally non-strangulating infarctions cover the various types of infections that can develop and cause abdominal pain. Also categorized as a kind of colic are gastric ulcers, an all too common form of colic caused by improper feed diets. Here is a list of different types of colics divided into the three main categories covered above.

Simple obstructions

Pelvic flexure impaction

  • Caused by an impaction of food material (feed or forage) or water in a region of the large bowel known as the pelvic flexure of the left colon. This is where the intestine makes a 180 degree turn and narrows.
  • Responds well to medical treatment, may require surgery if case is severe.
  • Can be fatal if left untreated.
  • Common in horses confined to boxes and/or receive large amounts of concentrated feeds. Horses with chewing difficulties are also at risk.

Spasmadic colic

  • Caused by an increase in peristaltic contraction inside a horse’s gastrointestinal tract. Can be a result of a mild gas buildup inside the gastro intestinal tract.
  • Signs are mild but responds well to spasmolytic and analgesic medication.

Ileal impaction

  • An impaction of the Ileum, the last part of the small intestine that ends in the cecum. Can be caused by an obstruction of feed or other things ingested by a horse. Or in some cases by other forms of obstruction such as roundworm or tapeworm.

Sand impaction

  • Occurs when a horse ingests sand as can happen with feeding surfaces that are un-elevated or from pastures that are sandy or have been heavily grazed leaving only dirt to ingest.
  • The sand can accumulate pelvic felxure, the right dorsal colon, and the cecum of the large intestine. Causing an obstruction.
  • The sand can irritate the lining of the bowel and cause diarrhea. If left untreated the weight and abrasion of the sand can inflammation of the bowel wall and even a reduction in colonic motility. In severe cases it can even cause peritonitis.
  • Colic responds well to medical treatment though severe cases may require surgery.


  • Enroliths are round hard balls of minerals that form around of ingested foreign material like sand or gravel.
  • Occurs in areas where grazing pastures are sandy or where an abundance of alfalfa is fed.
  • Will most often require surgery.

Strangulating obstruction

Left dorsal displacement

  • Occurs when the left dorsal colon becomes trapped above the spleen and against the nephrosplenic ligament.
  • May need surgery but can often be treated with simple exercise or phenylephrine. An anesthesia and rolling procedure must sometimes be performed.

Right dorsal displacement

  • Occurs when there is a displacement of the large bowel.
  • Signs may not be severe but surgery is often the only option.


  • Occurs when a part of the gastrointestinal tract twists upon itself. Often the small intestine or colon.
  • Occlusion of the blood supply to the twisted section makes this a painful condition with rapid deterioration.
  • Requires immediate emergency surgery.


  • Occurs when a section of intestine “telescopes” within a portion of itself.
  • Most common in small intestine of young horses.
  • Requires urgent surgery.

Epiploic Foramen Entrapment

  • Through rare, this occurs when a portion of the small intestine becomes trapped through the epiploic foramen.
  • The blood supply to the portion trapped is immediately occluded.
  • Surgery is the only treatment.

Stanulating Lipoma

  • Benign fatty tumors (lipomas) form on the mesentery.
  • When the tumor enlarges it wraps around a segment of the bowel and cuts off the blood supply.
  • Requires surgery.

Mesenteric rent entrapment

  • The mesentery is a thin sheet that is connected to the entire legnth of the intestine and sometimes a small tear in the mesentery can occur.
  • Entrapment of this kind occurs when a portion of the intestine  enters through the hole in the mesentery created by the tear. The entrapment causes the bowel to enlarge causing edema and reducing the chances of the section to exit the hole.
  • Requires surgery.

Non-strangulating infarctions

Large round worms

  • Common in young horses as a result of a very heavy worm infestation that can cause a blockage and even rupture the small intestine.
  • De-worming a heavily infected horse can cause a severe immune reaction to the dead worms. This can cause damage to the intestinal wall and cause fatal peritonitis.
  • Blockages to the small intestine, especially the ileum, may require surgery.
  • As horses develop an immunity to round warms between 6 months and year of age cases are rare in adult horses.


  • Acute diarrhea can be caused by cythostomes worms that are encysted as larvae in the bowel wall, particularly if large numbers emerge simultaneously.

Gastric ulceration

Though not technically part of the three categories described above, gastric ulcers fall under the definition of colics as they cause abdominal pains. They are caused by the constant production of acid in the stomach and are normally counteracted by saliva. Feed that does not allow a horse to chew for long periods of time will not absorb the necessary saliva needed to counteract the acid buildup in the stomach. This is what makes long stem hay and forage ideal for any horses diet. ETA-Equine has long stem mix blend hay developed exclusively for horses that will help combat some of the causes of gastric ulcers. With two different blends, the Township Blend and the Appalachian Blend,  It is the ideal forage for horses of all activity levels and types. Gastric Ulcers can also be caused by the following:

  • Confinement.
  • Infrequent feedings.
  • A high proportion of concentrated feeds, such as grains.
  • Excessive non-steroidal anti-inflammatory drug use.
  • Stress of different kinds (such as shipping and showering).