Skip to main content

Equine Digestive Problems

Why does digestive distress occur in horses?

The words “colic” and “ulcers” are enough to make most horse owners tremble in their boots. The modern equine lifestyle is very different from the one in which horses evolved, where they spent their time roaming 20 to 30 miles per day, continuously eating available forages along the way. In particular, the lifestyle of many performance horses usually involves travel, lots of stall time, high-grain diets and moderate to intense exercise. As with humans, all of this added stress can easily create digestive issues. 

How does the equine digestive system work?

To properly feed a horse, you must begin with an understanding of how their gastrointestinal system digests and absorbs nutrients.

After a horse swallows feed, that feed travels down the esophagus and reaches the stomach, which makes up only 10% of the entire digestive tract and is quite small relative to a horse’s total body size. Horses are classified as grazing animals because their stomachs were designed to digest small portions of food continuously throughout the day — which also means that their stomachs are continuously producing stomach acid, regardless of whether the horse is eating or not.

Next, feed reaches the small intestine, which is where fat, carbohydrate and protein digestion takes place due to the presence of digestive enzymes. This is the ideal location for grain to be digested and is the primary area from which minerals, vitamins and other nutrients are absorbed by the body. Interestingly, the small intestine also contains relatively small amounts of amylase, the main enzyme responsible for the digestion of starches and sugars — the major components of grain.

Finally, feed enters the large intestine, which is by far the biggest portion of the digestive tract. The large intestine is essentially a fermentation vat. A horse’s “gut microbiome” refers to the diverse population of microbes that live in the large intestine. These bacteria are key for the breakdown and utilization of forage and energy production.

What does this mean for my horse’s feeding program?

The modern horse is typically fed two to three meals per day, which means that its stomach is empty much of the time, with only stomach acid present. This largely contributes to the gastric ulcer issues experienced by many of today’s horses.

Additionally, horses are typically fed hay and grain at the same time. Given the option, every horse will choose to eat grain first and then move on to the hay, which pushes grain through the digestive tract faster, not giving it adequate time to be digested in the small intestine. When this occurs, grain becomes trapped in the large intestine, where it undergoes the fermentation process that was only meant for forages — all of which is bound to cause digestive upset.

While it might sound like the odds are against you when it comes to feeding the modern horse, simple solutions are available. Feeding the right ingredients, the right way and choosing supplements designed to specifically support the horse’s digestive system can make a big difference.

Common signs of digestive distress in horses:

  • Decreased performance and willingness
  • Reduced feed intake
  • Weight loss
  • Reactive to the girth/cinch
  • Arena sour
  • Looking and/or biting at flank region
  • Excessive rolling

Preventing digestive problems in horses

Utilize the tips below to help keep your horse’s digestive system in top shape:

  • Examine forage quantity and quality. High-quality hay plays an important role in every horse's diet. Make forage the number-one priority in your feeding regimen and offer it as much as possible throughout the day. Continuously feeding forage helps keep your horse’s digestive tract functioning smoothly. 
  • Feed the appropriate amount of grain and concentrates. Since the equine gut is sensitive to these types of products, you must be careful not to overfeed grains. You should also feed horses as individuals with unique needs. More grain is not always the answer for hard keepers. Instead, consider ration balancers, which are formulated to give your horse more concentrated nutrients in smaller quantities.
  • Feed hay before grain. Loading up the gut with hay first pushes the hay to where it needs to be in the digestive tract to be fully utilized: the hindgut. Feeding grain before hay can push grain through the small intestine too quickly, where it ends up in the hindgut, causing potential digestive distress or disease.