You are currently visiting our U.S.-based site.
MENU
Sign Up for Newsletters

Consultation: Nutritional Help for a Horse with DiarrheaBy Kentucky Equine Research Staff · January 28, 2016

From time to time, veterinarians contact the nutrition experts at Kentucky Equine Research (KER) for consultation on puzzling cases. As veterinarians, nutritionists, and many horse owners know all too well, horses have sensitive digestive systems, seemingly always on the brink of malfunction. The digestive tract is at the epicenter of this practitioner’s concern. Read on:

My client owns a 23-year-old Quarter Horse gelding that’s asked to do very little these days because of chronic lameness from advanced ringbone. He’s about 15.3 hands (160 cm) and weighs 950 lb (430 kg), so he’s moderately thin. Though he’s turned out all day, it’s a drylot, so his diet includes only hay. The hay is good-quality, about 70/30, grass and alfalfa (lucerne), respectively. He’s had diarrhea for about a year now. All tests come back normal, including fecal egg count for parasitism, sand accumulation, and bloodwork. The owner has always maintained his teeth well. Supplements we’ve tried include yucca, psyllium, and various probiotics. We’ve also tried adding more alfalfa and then less alfalfa with no difference in manure consistency or weight gain. We’ve also given the gelding a course of metronidazole, an antibacterial medication used to fight infections. None of this has worked. Do you have any other ideas?

One of the nutritionists at KER worked with this vet and horse owner to sort through this twofold problem, first addressing the chronic diarrhea and then the weight gain. The following summary represents an account of how two professionals collaborated to help an ailing horse. This is the nutritionist’s perspective:

Given his problem with compromised condition, I assume the gelding has hay at his disposal at all times. If this is not the case and hay is being fed in one or two meals a day, there is a chance he could be suffering from gastric ulcers, which might be contributing to the diarrhea. Without saliva and forage to buffer their natural acidity, gastric fluids can erode the stomach lining, creating ulcerations. Only an endoscopic examination will reveal definitively if ulcers are present. If they are, a course of omeprazole followed by daily antiulcer supplementation and free-choice forage will keep further gastric ulcers from developing. An uptick in alfalfa (lucerne) consumption could help with stomach health as well, as it contains some beneficial buffering qualities.

Given that you have tried many supplements on this gelding with no improvement, I would consider EquiShure, a hindgut buffer designed to moderate the pH of the cecum and colon through delivery of sodium bicarbonate. By balancing the pH, the microbial population can optimize fiber digestion which, in turn, might kick-start weight gain. Stabilization of the hindgut will increase water absorption and potentially decrease diarrhea.


Manure consistency can change quickly, sometimes in a week or two, with EquiShure.


EquiShure is a powdered supplement designed to be fed twice a day. Because this gelding does not get grain, the supplement can be given in an oral syringe mixed with a small amount of water. Another option would be offering it with a handful of soaked beet pulp if he is willing to eat that.  EquiShure should not come into contact with moisture until it is ready to be fed; otherwise, the time-release mechanism will trigger prematurely and may not reach the hindgut.

Manure consistency can change quickly, sometimes in a week or two, with EquiShure. Of course, changes in weight will take longer. If manure quality improves, you may consider revisiting the diet to include some concentrated sources of energy, which will help add condition. Adding a traditional sweet feed will help increase total calorie consumption. Concentrates high in oil might best be avoided, as sometimes these will soften manure consistency, but feeds with super fibers such as beet pulp and soy hulls can boost calorie intake. At times, these fiber-rich feeds might cause a horse to become gassy, so experimentation with adding calorie sources will provide the best answer for the gelding. At the very least, a balancer pellet or well-rounded vitamin and mineral supplement should be given to the gelding so that all of his nutrient requirements are met.

Sound feeding practices dictate that all new feeds be started gradually no matter the horse, but in the case of this gelding, it might be wise to be especially slow in offering a concentrated source of calories. Careful attention should be paid to manure consistency as new feeds are added. The same is true of hay; be sure to introduce new hay slowly and over a period of 7 to 10 days.

Other considerations:

  • No mention was made of herdmates. If the horse shares his drylot with one or more horses, observe the group at feeding time to ensure he gets his fair share of time at the feeder. Old horses tend to get pushed away from a hay source by domineering youngsters. If necessary, management strategies should be put into place to be sure the older gelding consumes appropriate forage and feed, and this might mean segregation for part of the day.
  • How the hay is fed might have an effect on your gelding. Some older horses with chronic neck or forelimb pain do not like to eat from the ground, as it places additional strain on aching body zones. Because this gelding suffers considerably from the effects of ringbone, the horse owner might try feeding hay from a feeder that sits high off the ground, at about chest level, so excessive weight is not placed on the forelimbs.
  • Mull over the idea of providing other high-quality forage such as hay pellets or cubes. Horses with healthy teeth have no trouble processing these fiber sources, and they can increase calorie ingestion significantly.

How did this collaborative effort between vet and nutritionist work out?

Indeed, after a few weeks on EquiShure, the gelding’s manure consistency began to improve and over the course of a couple more weeks became almost normal. Weight gain, as predicted, was slower, but in time the oldster’s weight crept up, increasing an entire point on the body condition scale.

The nutritionists at KER welcome the chance to work with veterinarians. If you or your vet has a question or concern about a horse’s nutritional management, we’d like to help.