A horse’s gut is a complex system responsible for breaking down feed, absorbing nutrients, and eliminating waste. Poor gut health can lead to a range of health problems in horses, such as weight loss, diarrhea, colic, or in the worst case even death. A well-functioning microbiome plays an important role in the health of the gut—and the entire horse. Every owner should have a basic understanding of how the equine digestive system works, what can happen if it doesn’t function properly, and how to support digestion so it remains optimally healthy and resilient.
The microbiome refers to the bacteria, viruses, and fungi present in the horse. The gut microbiome consists of billions of different microbes and is a complex, vital part of equine health. Each part of the digestive tract has its own microbial community, including the front portion (e.g., the mouth, stomach, and small intestine) and the hind portion (e.g., the cecum and large colon). These microbes are essential not only for digestion and nutrient absorption, but also for the body’s immune defense. The microbiome’s composition is established early in life, but later it is influenced by the horse’s lifestyle and environmental conditions. Diet, exercise, transport, medications, fasting, and stress are all known to affect the equine gut microbiome. Healthy horses tend to have broadly similar gut microbes, whereas in sick horses the presence of individual microbial species can vary significantly. As a result of gut microbiome disturbances, the horse’s microbiome can become abnormal and its diversity typically decreases.
Maintaining a healthy microbiome is extremely important for the horse’s health and digestive function.
1. Feed your horse enough fiber
Dietary fiber has numerous roles in the digestive system. Its primary benefits are seen in the large intestine, where microorganisms such as bacteria use fiber to produce energy and important nutrients such as B vitamins. If you choose feeds that are high in soluble fiber and low to moderate in starch, you support your horse’s gut microbiome.
These fiber-digesting bacteria play a key role in maintaining intestinal health by preventing the overgrowth of harmful bacterial species, while fiber breakdown produces heat and energy. Good sources of fiber include molassed and beet pulp products, flax, chia, or hemp, as well as soybean hulls. These high-fiber feed options contain less starch and sugar compared to traditional grain-based feeds. High-starch feeds can cause serious problems such as gas colic or laminitis, as well as acidification of the gut.
2. Reduce your horse’s stress
Environmental stressors can affect not only the digestive system but also the gut microbiome. Stressors such as changes in living conditions, weather fluctuations, changes in feeding routines, and exposure to new or stressful situations can trigger a chain reaction in the horse’s body. Such factors can disrupt normal gastrointestinal function.
3. Feed little and often
A horse’s stomach is about the size of a football and has a capacity of roughly nine to fifteen liters, so it cannot tolerate large meals at once. To support efficient digestion, it is important to feed small portions frequently. If a horse is given a large amount of concentrates in one feeding, the feed passes through the digestive tract more quickly, leaving less time for nutrient absorption. This also increases the risk of digestive upset.
Grains and sweet feeds high in sugar contain large amounts of sugars and starch. Feeding excessive sugars and starch can disrupt the balance of microorganisms in the large intestine, which is naturally adapted to digest grass and forage. This imbalance can lead to gas formation, causing discomfort and potentially colic signs. In addition, excessive sugar and starch intake can trigger laminitis, a serious inflammation of the soft tissues within the hoof.
4. Regular feeding times
One of the easiest ways to maintain gut health is to feed your horse at consistent intervals every day. The bacteria in the horse’s digestive tract thrive when their environment remains stable. Sudden dietary changes can reduce beneficial bacteria as conditions become less favorable for them. This, in turn, can allow harmful bacteria to proliferate, potentially causing problems in the digestive system.
5. Make dietary changes slowly
When changing your horse’s diet, it is important to do so gradually. This gives the horse’s gut microbiome—its gastrointestinal microorganisms—time to adapt to new feed sources. This significantly reduces the risk of complications such as colic and the production of harmful toxins.
6. Feed according to the horse’s size and workload
One of the biggest problems for today’s (leisure) horses is overfeeding relative to exercise and energy expenditure. Obesity predisposes horses to many diseases and problems, including poor gut condition and related risks. It is important to monitor body condition and fat cover, especially if the horse is prone to laminitis or other metabolic disorders (EMS, PPID).
7. Feed only clean, high-quality forage
Hay fed to horses should be dust-free, free of mold, and otherwise of good quality. Hay should contain enough stem and fiber. This can help prevent digestive disturbances and reduce the risk of disease-causing microorganisms.
When evaluating gut health, it is also worth considering the effects of sand. Horses can ingest sand while grazing or eating from the ground. Over time, sand can accumulate in the intestines and cause digestive issues such as diarrhea and colic. If horses are fed in sandy paddocks, hay can be offered on rubber mats or in feeders to reduce sand intake. Regular psyllium or chia courses can help prevent harmful sand accumulation.
8. Keep water available at all times
A horse must always have access to fresh, clean water to prevent dehydration. Lukewarm water is the gentlest option for the digestive tract. About two-thirds of a horse’s body is water, and horses may drink up to 45 liters per day. You should always offer water—especially after exercise. This helps keep the digestive system functioning. Insufficient drinking can cause constipation, which can even lead to colic.
Soaked feeds are a good way to add extra fluid. Horses that drink poorly, avoid cold water in winter, or travel for competitions particularly benefit from additional fluids or feeds soaked in water. These feeds often contain digestible fiber that releases water readily in the digestive tract.
9. Regular dental checks
A horse must chew feed properly in order to digest it efficiently. As horses age, they are more likely to develop dental problems, which can make chewing difficult and compromise digestion and overall health. It is important to ensure that horses with poor teeth have access to fiber sources they can chew easily. Fiber is essential for gut health and helps keep the digestive system functioning.
If your horse has poor teeth, good easy-to-chew fiber-rich options include:
- Soaked hay – softer and easier to chew.
- Chopped hay – easier to chew than long hay stems.
- Hay cubes – a good option for horses with very poor dentition.
- Beet pulp – a high-fiber feed that can be soaked or fed dry.
10. Reduce grains and complete feeds if you can
Many horses do not need as many carbohydrates as they are commonly fed. Overfeeding can lead to multiple health problems such as obesity, laminitis, insulin resistance, and metabolic syndrome. Overloading the digestive system with energy-dense feeds can also cause digestive disturbances. To avoid these issues, it is recommended to feed low-carbohydrate, high-fiber feeds.
11. Monitor deworming status
Parasites must also be considered when maintaining gut health. They can have a significant impact on overall gastrointestinal health. Regular fecal egg counts are a good way to assess parasite burden and the need for deworming. Parasite load is also easy to reduce by cleaning paddocks and pastures.
Related products:
Chia seeds
Milled Hemp Seeds
Inulin
Gastro Clay B
Protect That Tummy
Mash the Pony
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Electrolyte Up
