Designed for foraging on small amounts of roughage throughout the day, the horse is a flight animal, and can run at a moment’s notice without being bogged down by big feed loads.
Unfortunately, most horse owners do not have the luxury of letting their horses out to graze on endless pastures. For the most part, horses are often fed large amounts of concentrate once or twice a day. This can greatly undermine a horse’s digestive process.
If there is not enough forage going through the serpentine small intestine, it can cause kinks and colic tie-ups. If too much unassimilated starch/sugar enters the cecum (where the majority of the microbial digestion takes place), you get a population bloom of sugar-eating microbes. The microbes that are designed to eat the high-fiber forage, suffer. This creates imbalance, excess acid forms and begins to do damage, creating a toxic environment.
This Is Where Trouble Starts
Horses produce less amylase, the starch and sugar digestive enzyme, than most other animals do. Therefore, the chances are greater for undigested starch from grains and sugar from molasses reaching the hindgut.
Elevated levels of starch and sugar reaching the cecum, force a shift in the microbial population, lowering pH, and often allowing pathogenic microbes to gain a foothold. Also, with greater acidity comes cell wall damage which can lead to digestive colic.