Digestive Tract

The horse has a foregut and hindgut.

Foregut:

• stomach
• small intestine

Digestive enzymes in the foregut allow starches, sugars, fats and proteins to be broken down and absorbed into the bloodstream. Very little fiber gets broken down here because the horse has no enzymes to digest fiber in the foregut.

Hindgut:

• cecum
• colon

In the hindgut, digestion is aided by billions of microorganisms (healthy bacteria or microflora) whose main function is to digest fiber.

When a horse is overfed grain (starches and sugars), the horse doesn’t have the capacity to digest it all in the foregut, so some of it may pass along undigested into the hindgut. The hindgut is not well equipped to digest large amounts of soluble carbohydrates (sugars and starches). That’s why overfeeding grain often results in excess gas production and increased risk of colic and laminitis. Consequently, for a 1,000-1,100 pound horse, grain meals should be no larger than five to six pounds.

Purina veterinarians and Ph.D. equine nutritionists have authored numerous articles about specific digestive issues. Scroll through the topics listed below. To view the full text of an article, simply click on the title.