Healthy as a Horse – Gut Health Affects the Whole Body

Healthy as a Horse – Understanding Gut Health

A Guide to Understanding Gut Health as the Foundation for Overall Horse Health

The health of your horse's gut affects almost everything in his body and mind. If the gut is healthy, you have a healthy horse; if the gut is out of balance, you'll see a domino effect of cascading health problems. With the digestive system in balance the body is better equipped to maintain internal stability. This means it can better adjust to changing external conditions. It will be be more resilient and stable, resulting in increased vitality, better performance, recovery, willingness, and focus. It is easy to understand the importance of the gut when you consider that 70% of the immune system resides in the gut.

Horse digestive system












In this article, we will walk you through everything you need to know step by step. We will explain how the gut works and how it affects your horses' health. We will also present solutions for keeping your horse healthy or restoring health if the body is out of balance.

You will know that the gut is out of balance when you see obvious symptoms like ulcers, diarrhea, and weight or appetite changes. There are also less obvious symptoms like resilience, comfort, condition, willingness, and focus that can be traced back to gut issues.

To understand these complex connections, let's begin by looking at how the gut works.


How the Gut Works 

The horse's GI tract begins with the mouth. Good teeth break down the food into smaller pieces. Saliva is generated to lubricate and further break down food particles and to soften them for the journey.

Then the food travels down the five feet long esophagus, a smooth muscular tube that contracts to advance food downwards in a wave-like motion to the stomach. This lubrication from salvia is essential to ensure that no food gets stuck and arrives safely in the stomach.











The stomach consists of an upper and a lower region. The lower glandular region produces hydrochloric acid that helps to further break down the food. It also secretes mucus to protect the stomach lining from the acid. The upper squamous region is not protected by mucus. It is more susceptible to ulcers than the lower region. The stomach constantly secretes acid because horses were designed to graze all day. That is why it is best to feed them frequent small portions of high-quality high-fiber foods. The stomach's PH in the non-glandular or squamous upper region should be between 6 and 7. The PH is much less in the lower section, between 1 and 2. A healthy acid balance is essential. You need enough acid to properly break down food into nutrients, but too much acid will damage the stomach lining and can lead to ulcers.

Next on the journey are the small intestines. When the stomach is about 2/3rds full, nutrients are moved to the small intestines even if not everything is digested. Enzymes that are secreted from the pancreas help to further liquify food particles so they are ready for absorption into the bloodstream. The nutrients are absorbed through the villi. The villi is the lining of the small intestines, which consists of tiny outgrowths. They look like small suction cups of mini fingers. They trap food particles and make absorption easier by increasing the surface area of the lining. The villi contain a lot of blood arteries into which the nutrients are absorbed. Via the blood, the nutrients are then delivered to the cells that need them. Those nutrients are simple carbohydrates, proteins, essential vitamins, and fats and provide energy for all body functions.

intestine villi

Any still undigested or unabsorbed food residue then moves into the hindgut. The cecum, the large colon, and the small colon make up the hindgut. Food residue moves from the small intestines through the cecum into the large intestines. The large intestines make up the largest portion of the horse's digestive tract. The purpose of the hindgut is primarily to ferment anything that was not digested in the foregut by enzymes. Billions of microbes go to work. They are called the microbiome, and they consist of good bacteria and protozoa. They like a PH of 6-7, and their job is to ferment what is left of the digesta. They convert fiber to volatile fatty acids, which provide energy. The hindgut also absorbs water, electrolytes, vitamins, and minerals, especially Vitamin B, and synthesizes amino acids. The microbiome adapts to what your horse eats and is unique to them.

The lining in the large intestines is designed to allow the absorption of beneficial nutrients but also acts as a barrier for non-beneficial food remnants or toxins. It is called the intestinal barrier.

The last stop is the small colon. It ends at the rectum and anus. Excess water is absorbed in the form of fecal balls. They are excreted in the healthy gut via the poop shoot, about 50 pounds a day for 1000-pound horse.


When Things Go Wrong…

It is a masterfully designed system, and if everything is harmoniously balanced, you have a healthy gut and a healthy horse. But unfortunately, it is easy for things to go wrong. The horse's gut is designed for two vital priorities: getting nutrients to the right places and ensuring that any harmful substances are excreted so they can not cause any damage. Let's take the same journey we traveled above to explore how the gut works and look at what can go wrong.

The journey begins with the mouth. If the teeth are not in good condition, the horse doesn't break down the food into smaller pieces, which can cause problems downstream. To safely travel down the esophagus, the food needs to be chewed and lubricated by saliva.

When food is too big and without enough lubrication from saliva, it will have trouble moving through the esophagus. Your horse will have difficulty swallowing, and in more severe cases, if food gets stuck, you have an esophageal obstruction and choking. That is an emergency situation that requires immediate veterinary care.

…In the Stomach

The next stop is the stomach, where a balanced PH is the key to good health. The horse is designed to graze constantly and therefore produces stomach acid all the time. It is vital to have a full stomach to "keep the acid busy." When the PH is out of balance, things go wrong. Too little acid results in the food not being broken down enough, and then it can't be adequately absorbed in the villi of the small intestines. When there is too much stomach acid, it damages the protective mucus layer and results in ulcers.

Let's look at how stomach acid gets out of balance.

FEEDING: When horses don't graze and are fed less frequently, there are times when no or not enough food fills up the stomach. The acid then has nothing to digest, and damages the stomach lining. Horses produce up to 16 gallons of acidic gastric juice each day. When there is not enough food in the stomach, acid can swoosh around and splash areas of the upper stomach that are not protected by squamous mucosa lining. The type of food also makes a difference. When you feed foods that contain cereal grains and are high in sugar or graze on high fructan grasses, they pass through the stomach quicker than forage. You then have the same problem, not enough food in the stomach to give the acid something to work on, so it goes to work on the stomach lining. Ideally, your horse should be grazing all day, but that is not practical in all situations. The best way to protect your horses when that occurs is to supplement a GI balancer that restores the horses' ideal PH.  If possible, change your feeding protocol to include more forage, use slow feeders or grazing hay nets, and feed more frequently.

STRESS: Stress is as bad for horses as it is for us. Horses experience stress in physical and psychological ways. Frequent trailering is hard on horses, and show or competition environments can be stressful. When horses are not turned out frequently, confinement and social isolation can cause stress, and so can extensive training. When a horse stresses, it releases the hormone cortisol. Cortisol is part of the natural flight response in short increments, but prolonged exposure is damaging. The release of cortisol decreases the production of prostaglandins, which are an integral part of the protective mucus production that safeguards the stomach wall. Other consequences of stress can be reduced blood flow to the digestive system, decreased saliva, and decreased absorption of nutrients. To protect your horses, try to reduce stress as much as possible. But we all know that in real life, that is not always feasible. Fortunately, there are great supplements you can use to balance your horses' stomachs and keep them healthy.

MEDICATIONS: Medications can be necessary and life-saving, but they do not come without consequences. Non-steroidal anti-inflammatory drugs, commonly known as NSAIDS, are used for pain and inflammation. When administered orally, they pass through the stomach. NSAIDs inhibit prostaglandins, which means that prolonged use can lead to less mucous production and can lower the PH in the stomach. The lower PH puts your horse at risk for ulcers. There are two ways you can help your horse. First, whenever possible, consider using a holistic remedy for pain and inflammation like RepairRX. Second, use supplements like a GI balancer to restore your horse's PH balance when you have to give NSAIDs to offset potential damage to the stomach lining.

Omeprazole is frequently administered when a horse has ulcers. It is a proton pump inhibitor that inhibits acid production. It can be helpful and necessary when your horse suffers from ulcers, but it comes at a cost. The damaging side effects of using proton pump inhibitors are seen not just in the stomach, they reach further downstream. In the stomach, the acid's job is to further break down the food particles for absorption. When you inhibit acid production, your horse does not have enough acid to do this critical job. This can lead to malnutrition and hindgut acidosis or leaky gut, which we will discuss further as we continue our journey through the horse's intestinal tract.

…In the Small Intestines

The small intestines are where nutrients are absorbed. When everything is balanced, juices from the pancreas continue to break down food particles into absorbable nutrients, which are absorbed through the villi. Some of the problems we see in the small intestines originate upstream. A horse with dental issues who is not properly chewing his food ends up with food particles that are not as processed as they should be at that stage. The same happens if there is not enough stomach acid to break down food particles due to the horse being on proton pump inhibitors. This can result in fewer nutrients being absorbed by the villi and less energy being delivered to where it is needed, and the horse experiences malnutrition. In addition, those unabsorbable food particles spill over into the hindgut, where they can cause additional problems.

intestine villi

Another problem is atrophy. The tiny finger-like outgrowths in the villi lining will atrophy with age, but there are other factors that prematurely diminish the villi. Those are stress, bacterial overgrowth, and sugary, starchy processed foods. If you feed too much starch, even healthy villi can't absorb all of it because those foods move through the digestive tract fairly fast, and the enzymes can't digest all the starch. Sugary cool-season grasses contain a lot of fructans, which the villi can't absorb. Those also move on to the hindgut.

…In the Hindgut

Anything not absorbed in the small intestines is transported into the hindgut. It is the largest part of the horse's digestive system. It works like a big fermentation container where billions of microbes consisting of good bacteria and Protozoa  go to work on the digesta. This produces vital energy, amino acids, minerals, and vitamins. When things go wrong, a wide range of problems can occur, from colic to dysbiosis (leaky gut syndrome), hindgut acidosis, and colonic ulcers.

HINDGUT ACIDOSIS & COLONIC ULCERS: We have explored the causes of high acid in the stomach, like too many starchy foods and not enough forage to keep the acid busy, stress, or NSAIDs. The extra acid in the stomach now travels to the hindgut. In addition, bacterial fermentation turns the undigested starch that wasn't absorbed in the small intestines into lactic acid. This highly acidic condition is called hindgut acidosis. Hindgut acidosis can damage the intestinal wall and create an environment favorable to colonic ulcers.

MICROBIAL IMBALANCE & LEAKY GUT: Billions of bacteria reside in the hindgut. When their balance is disturbed, you have hindgut dysbiosis. These microbes, many of them bacteria, that ferment fiber in the hindgut are sensitive to acid. That increased acid can disrupt this delicate microbial balance and lead to a die-off. When that happens, endotoxins are released. The intestinal wall is naturally permeable but designed to let only nutrients through and keep toxins out (intestinal barrier). When the increased acid and inflammatory response damage the lining of the intestinal wall, toxins are now able to enter the bloodstream and wreak havoc on your horse's health. Those toxins can cause a cascading range of problems. When toxins and pathogens leak through the damaged intestinal wall into the bloodstream, that is called 'Leaky Gut.' It can cause inflammation and escalate to a chronic inflammatory state, and lead to colic, laminitis, and insulin resistance. It also triggers an immune response propelling the endocrine system into overdrive.

To prevent hindgut problems, feed a balanced high-forage diet, feed small frequent meals, and support your horse with PH-balancing and probiotic GI supplements. To heal the lining of the intestinal wall, choose supplements with therapeutic doses of bioavailable colostrum, bioactive immunoglobulins and prebiotic factors. Consider putting your horse on a comprehensive, holistic gut repair program. Above all, be proactive! You know what stresses your horse. When traveling, provide additional gut support. Anytime antibiotics are used, it is vital to supplement good bacteria to restore microbial balance. Be vigilant of any stressors, and when prevention isn't possible, choose to support your horse with GI-balancing gut supplements.


In Summary

Horses have delicate digestive systems, but with the right tools, you can support your horses holistically to keep them healthy and recover from even severe gut issues.

Feel free to reach out with any questions you may have.