Salt Supplementation and Gastric Health in Horses

Previous data generated from horses and other species suggest that high-salt diets negatively affect the gastric mucosa, known also as the stomach lining. However, electrolyte solutions containing a high level of salt benefit sweaty horses following exercise by replacing sodium and chloride and encouraging rehydration. According to German researchers, a pelleted sodium chloride feed offered to horses was a palatable, safe way to replace electrolytes lost from sweating in exercising horses with no observable negative effects on the gastric mucosa.^*

“A previous study found that repeated electrolyte supplementation worsened gastric ulcers, making some owners of horses prone to ulcers cautious about electrolyte supplementation,” explained Catherine Whitehouse, M.S., a Kentucky Equine Research nutrition advisor. “The current study used a more practical electrolyte supplementation model to investigate the effects of electrolyte supplements on the gastric mucosa. Gastric ulcers contribute to poor performance and have other negative health effects, including weight loss and recurrent colic.”

To assess the effect of a sodium chloride pellet on gastric health, researchers pelleted sodium chloride with palatable ingredients such as barley and dried grass. Fifteen three-year-old Warmbloods in training were recruited for a study. The pellet was fed at a dose calculated to compensate for 10 liters (2.6 gallons) of sweat loss per day, providing 30 g sodium and 39 g chloride per day, divided into two meals. A placebo pellet was formulated to include all other ingredients at the same percentages as the sodium chloride pellet without the electrolytes.

On day 0, the horses’ stomachs were evaluated via gastroscopy to directly visualize the gastric mucosa. Horses were then offered the sodium chloride pellet or placebo for 19 days, and a second gastroscopy was performed on day 21.

“The initial prevalence of gastric ulcers at the start of the study was 83%, and sodium chloride did not have any negative effects on the gastric mucosa throughout the study period,” Whitehouse said.

The researchers concluded that sodium chloride pellets appear to be a safe, convenient, and effective way to replace certain electrolyte losses in horses. They also hypothesized that a longer supplementation period would also not harm the gastric mucosa, though further studies are needed.

They also noted that fresh water should always be made available to horses offered an electrolyte supplement.

“Most of the horses had gastric ulcers at the start of the study, showing how prevalent this condition is in Warmblood horses in training. Both glandular and squamous ulcers were observed,” Whitehouse noted.

“Supplementing with electrolytes is an essential part of nourishing performance horses, as electrolytes replace minerals lost in sweat, support hydration, and maintain muscle function,” Whitehouse shared.

She added, “I recommended mixing salt or an electrolyte supplement with feed to help buffer gastric contents and dilute the electrolyte concentration per meal. This method is preferred for daily electrolyte supplementation, and the electrolyte should be split into as many meals as possible to help with palatability. When electrolyte pastes are needed, provide a small forage meal prior to giving the product to prevent dosing on an empty stomach.”

Restore Paste, developed by Kentucky Equine Research, is a carefully formulated electrolyte supplement designed to match the composition of sweat. This easy-to-administer product replaces chloride, sodium, potassium, and magnesium and contains a gastric buffer to support gastrointestinal comfort.

 ^*Alshut, F., M. Venner, G. Martinsson, and I. Vervuert. 2023. The effects of feeding sodium chloride pellets on the gastric mucosa, acid-base, and mineral status in exercising horses. Journal of Veterinary Internal Medicine 37(6):2552-2561.