For such a big animal, the horse has a surprisingly delicate digestive system. So much so that you’ll want to make protecting it a priority. A good place to start is by asking yourself a few questions about your current management practices. This bit of guided introspection can help you identify areas you could adjust or improve. Here are the questions that will reveal some of the most useful information:
1. Does your horse get regular turnout?
The key to keeping a horse’s digestive system functioning well is to mimic his natural living conditions as closely as possible. Horses with access to ample pasture will spend as much as 18 hours a day grazing. That’s exactly what their digestive tracts are designed for—a near-continuous supply of chewed grass. The slow, continual walking associated with grazing also helps encourage gut motility. It’s not just a theory: Research confirms that horses on full turnout almost never experience colic.
This doesn’t mean that every horse should be turned out on pasture full-time, though. Some horses have health issues, such as a susceptibility to laminitis, that require their access to pasture be limited. And some easy keepers get dangerously fat if allowed to graze around the clock. But even those horses who need their grass intake limited—a muzzle is a good way to do this—will still benefit from the exercise and socialization they gain from spending most of their time on pasture.
2. Does your horse ever “go hungry” during the day?
The common practice of feeding a horse one or two large meals per day is partially responsible for the ubiquity of equine ulcers. A horse’s stomach produces acid continuously, even when he’s not eating. When the acid accumulates in an empty stomach—such as during the long stretches between meals—it damages the lining, leading to painful ulcers.
In contrast, feeding a horse free-choice hay, allowing him to graze on turnout around the clock, or feeding him many small meals a day, keeps a steady supply of buffering saliva moving into the stomach to neutralize the ulcer-causing acids. If you need to limit your horse’s hay ration for health reasons, try offering it in a slow feeder. This limits the amount he can pull out in each bite, extending mealtime and reducing waste. You can also divide his hay and grain into multiple smaller portions that you feed throughout the day.
You could also consider including a little alfalfa in the mix. Research has shown that alfalfa hay is more efficient at buffering against stomach acid than grass hay, due to the higher level of calcium in the alfalfa.
3. Are you feeding dietary concentrates in a thoughtful way?
Some horses—growing youngsters, broodmares, elderly pensioners, hard-working athletes, for example—require more calories and nutrition than forage alone can provide. For centuries, grains were used to fill that gap. In more recent times, concentrates such as sweet feed and pellets have been the solution.
However, we know today that excess amounts of grains and other high-sugar, high-starch concentrates can lead to significant digestive problems in horses. Consider how a horse’s digestive tract functions: To utilize a fibrous food like grass, herbivores must ferment what they eat. Most herbivores are ruminants—animals such as cows, sheep, goats, deer and camels—which have multiple stomachs.
One of these serves as a large fermentation area. Horses, however, have a single, relatively small stomach. It holds only two to five gallons, compared to a cow’s, which holds 15 to 30. This single stomach empties into the small intestine and then the hindgut, which is where fermentation in the equine digestive tract occurs. Feeding excess grain and concentrates, particularly in a short period of time, dumps more sugar and starch into a horse’s hindgut than he is equipped to handle. This disrupts the delicate balance of organisms there, leading to digestive upset.
Excess grains and concentrates can also increase a horse’s risk of gastric ulcers in a few ways. For starters, saliva has a buffering effect on stomach acids, but a horse produces much less saliva when he chews grains rather than hay. Grains and other concentrates also stimulate the production of a hormone in the stomach that converts sugars and starches into volatile fatty acids, which can increase the damage to his stomach lining.
Not all concentrates cause digestive problems. If your horse needs more calories than he can get from forages alone, look for “low starch/high fat” feeds that derive more calories from fats than from starches and sugar. In addition, many commercial feeds formulated to support digestive health are available.
4. Does your horse have continuous access to water?
The average horse will drink about seven gallons per day, given the chance. The actual amount may vary; if, for example, he’s eating drier hay, he will drink more than when he’s grazing moisture-rich grass. Most horses naturally drink what they need if they have access to clean water.
Rather than calculating your horse’s water needs in terms of gallons per day, think of hydration this way: A horse needs as much water as he will drink. Simply chewing and digesting dry forage requires plenty of fluid, but the more important role of water in digestive health is keeping ingesta moving. If there’s not enough water in his digestive system, the ingesta form impactions that block the further flow of food, causing potentially serious colic.
It’s crucial, however, that you make water available in a way your horse can easily access it. This means checking your horse’s water sources daily, and multiple times a day in hot weather. Troughs and buckets need to be clean and full, and automatic waterers need to be fully functional. Make sure the water itself isn’t too hot or too cold—both extremes can discourage drinking. In group turnout situations, make sure timid horses are given access to the water by bolder herd members and that the footing around the trough isn’t treacherous for an older or frail horse.
Above all, don’t withhold water from a horse after exercise. The idea that allowing hot horses to drink cold water leads to muscle cramps and colic is a myth that has been disproved by several studies.
5. How do you feed your hay?
In general, it’s best to feed hay from the ground. Hay fed from elevated nets and racks can rain dust down into a horse’s eyes. Furthermore, when a horse lowers his head to eat, gravity helps drain fluids containing dust and particles.
However, if you have sandy soil, a horse eating off bare ground can ingest enough of the particles to cause sand colic. If you live in an area with even slightly sandy soil, it’s a good idea to feed hay off a stall mat and place your horse’s feed tub on or over the mat, as well. Clean the mat with a broom daily and keep it free from sand and dirt. You may also want to add psyllium to your horse’s diet. Made from the ground seeds of Plantago plants, psyllium swells and forms a gel-like substance when ingested. In people, as well as horses, it’s a proven laxative.
Your answers to these questions can help you identify adjust- ments you could make to protect or enhance your horse’s digestive health. If you are unsure of what’s best for your horse, consult with your veterinarian and/or an equine nutritionist. As always, make changes to your horse’s feed regimen—including hay—gradually and with care.