What is Colic in horses

Colic is a general term that refers to gut pain in horses, which can be from a variety of causes. Colic is often caused by the feed and feeding practices. There are three main types of Colic in horses:

• Tympanitic - colic also known as bloat or wind colic. It is defined as an acute continuous pain caused by the overproduction of gas which distends the gut.
• Spasmodic - most common type of colic is usually quite mild affecting younger horses. It simply is the pain associated with the contraction and/or the spasm of a portion of the small intestine (B).
• Obstructive - (eg twisted bowel and Sand Colic).

How do I know my horse has Colic

The symptoms of Tympanitic colic are;

• Sweating
• Elevated heart rate and increased temperature
• Tense or firm abdomen
• Horse makes violent attempts to lie down and appears anxious
• Attempts to urinate frequently and flatulence

Symptoms of spasmodic colic are;

• Elevated heart rate and rectal temperature
• Sweating, restlessness and tense abdomen
• Bouts of acute pain interspersed with periods of normality

What causes Colic in horses

This type of colic is caused by rapid changes in feed or excessive fermentable sugar and starch (NSC) intake, resulting in the fermentation within the stomach (A) and the hindgut (C). Tympanitic colic can be differentiated from other types of colic through the sound that the gut makes when the stomach is tapped (it resonates as if hollow), and the bloated appearance of the abdomen.

Some of the main causes of this colic is the migration of parasites through the digestive system and dehydration, or Dysbiosis. This kind of colic is not usually severe but any large spasms within the gut can lead to the displacement of the large intestine (D) which is an emergency.

How diet helps Colic in horses

To avoid Tympanitic colic, reduce the NSC content of the feed so as to reduce the substrates that can be fermented to produce gas. To treat a horse with Tympanitic colic, it is suggested to reduce the NSC intake, and feed an oil to reduce the fermentation in the gut. In order to avoid this type of colic in pasture fed horses. Also limit the grazing time on fresh spring grass, reduce the amount of grain (high NSC feed) fed, and feed a medium quality grass hay.

To avoid spasmodic colic, ensure the horse is treated for parasites. Dysbiosis refers to the abnormal growth of normal intestinal microorganisms caused by excessive amounts of sugars passing to the intestines which are then being used as food by these organisms. The excessive growth of these organisms is linked to "leaky guy syndrome", which can cause colic. This syndrome may be avoided by feeding low NSC feeds, and oils containing MCT that have antimicrobial actions to preserve gut health.

Understanding how some feeds cause colic, and how some feeds avoid colic will help you select feeds suitable for your horse to maintain long term health and performance.

It is suggested that feeds containing levels of NSC >12% can cause Tympanitic colic. It is also suggested that oil in the feed can assist the movement of digesta through the gut.