Equine Myth Busters: Gut Health

Owning horses is like having potato chips, you can’t have just one. With each horse comes a labor of love in ensuring they are well managed, especially when it comes to overseeing their gut function and keeping them free of colic, ulcers, and other gastric distress. Depending on your farm’s location and overall farm management, the ingestion of sand might be unavoidable in your horses. In the quest to keep our horse’s digestive systems happy and healthy, the singular most important nutrient a horse needs is water. Sufficient water intake is the first key to maintaining proper gut function. Let’s explore a common misconception when it comes to keeping the equine gut healthy, usually with prevention of colic at the front of our minds. We will decode how a popular gut remedy works and decide if it’s worth the investment or potentially a gimmick.

When it comes to prevention maintenance there are endless products on the market, and it is easy to leave money on the table in feeding our equine athletes. The first area of prevention maintenance in many barns are high fiber psyllium products used as a laxative to clear sand build up in the gut. The age-old technique is to feed horses these products monthly to purge the GI tract of sand, to minimize the potential of sand colic. The psyllium swells in the stomach, collecting the sand to be passed in the manure, at least this is the theory. Unfortunately, research does not necessarily support this theory and there is only mere anecdotal evidence. Let’s look at the equine digestive tract to understand where these products fall short. Once a horse consumes a meal it is funneled from the esophagus to its small stomach where breakdown and absorption of feed begins before passing to the small intestine where most digestion and absorption occurs. Enzymes help break down food particles and nutrients are absorbed through the walls of the small intestine and into the bloodstream to be passed where they are needed. Any feed particles that are left undigested from the small intestine head to the last stop in the digestive system, the large intestine or cecum which comprises nearly 60% of the horse’s digestive tract. This high-functioning large intestine houses many microorganisms and is the reason horses can break the cellulose bonds of forage and derive nutrients from it.  Most of the sand a horse picks up through grazing or other means ends up in the cecum.

Let’s let logic seep in to see how psyllium is not quite the hero we always thought it was. Feeding many psyllium products on the market to our horses is like any other meal to the digestive tract although it does contain more fiber than many grains, in that it is likely to be broken down by the small intestine. To be effective in removing sand build up, these products must make it to the cecum. However, there is not enough fiber in the recommended dose of these products to effectively reach the cecum and remove the accumulated sand.

We like to bring solutions here, so let’s investigate other management tips to aid in the inevitable instance of sand in the gut. The first tip might seem obvious but reduce exposure to sand when possible, such as feeding your horse using hay nets or mangers and placing rubber mats under feed tubs. In Florida keeping sand out of reach is not so simple, and consumption of sand is likely at some point.  We need a solution that will make it to the cecum, let’s focus on forage! A good amount of roughage in the diet is the recommended solution for maintaining a happy, sand-free gut. This is because forage is broken down in the cecum by the microbes that live there and can keep sand from accumulating as it passes through. A horse should eat 1.5-2% of its body weight in forage daily.

So far, feeding psyllium to prevent or to treat sand in the equine gut is a myth according to science. A better approach is simply enforcing a high fiber diet, using hays and fresh forages to meet the nutritional needs of the horse when possible. As horse owners, there are plenty of ways to spend money at the feed store, be sure to spend in areas that are proven effective, otherwise, buy yourself something nice.

For an additional explanation, have a look at this study done at the University of Florida, “Failure of Psylium Muculloid to Hasten Evacuation of Sand From the Large Intestine”, Hammcok et al. Failure of Psyllium Mucilloid to Hasten Evacuation of Sand From the Equine Large Intestine (ufl.edu)