The bacterial community of the horse gastrointestinal tract and its relation to fermentative acidosis, laminitis, colic, and stomach ulcers.

The gastrointestinal tract of the horse has unique characteristics that make it well suited for the ingestion and utilization of roughage. The horse is considered a simple-stomached herbivore and is classed as a hindgut fermenter. The upper segments of the gastrointestinal tract resemble those of a typical simple-stomached animal. The lower have undergone modification to become voluminous and host to a large number of microbial populations similar to those of the compartmental stomach of ruminant animals. The main advantage of this arrangement is the ability of the horse to extract valuable nutrients from the diet before digesta reaches the hindgut where the rigid structural components that resisted enzymatic digestion at the small intestinal level undergo extensive fermentation processes.