Is Variable Salt Intake Normal?

A horse owner wonders why some horses gobble their salt blocks while others hardly touch theirs.

Q I once had an older Tennessee Walking Horse gelding that would literally eat his salt block, scraping at it with his teeth. I’ve also known horses that completely ignore their salt blocks. Why the difference, and is either behavior unhealthy? Did my gelding’s age or breed have anything to do with it?


A There are no age, gender, or breed predilections that influence the voluntary salt intake of an individual horse. Salt helps maintain electrolyte and water balance in horses as it does in all animals, and certain individuals may consume more or less salt than others based on need and preferences.

The best approach is to provide a salt block and allow voluntary intake, while limiting the amount of salt for horses that gobble it. Plain salt blocks are white, and made of the same type of salt as we keep on our tables. The red blocks, known as mineral blocks, include other ingredients—such as magnesium, cobalt, potassium, and vitamins—in addition to salt.

Mineral blocks often contain molasses and other sweeteners, too; for this reason, some horses enjoy eating them or may even become addicted to eating them. Some horses enjoy salt more than others and will spend more time licking a block; others will lick at either block, white or red, due simply to boredom.

Horses that consume salt or mineral blocks quickly—say, within days to a week—should have their intake limited. A good solution in those cases is to put a small block in with the horse at monthly intervals.

Horses consuming a balanced diet (including pasture and/or good quality hay, with or without a concentrate) won’t typically need further salt supplementation beyond the block. There’s also no concern regarding horses with no interest in the salt block. We don’t advise top-dressing a horse’s concentrate ration with salt as this may affect palatability and perhaps result in a refusal to eat the grain.

Do be aware that temperature can affect a horse’s need or desire for salt. A horse performing in 100-degree heat especially needs free-choice access to salt and, of course, water. Salt will encourage water consumption, a dynamic that can be of critical importance in hot, dry climates.

A horse’s activity level can also play a role in salt intake, and animals working as hard and long as endurance horses, for example, may need salt/electrolyte supplementation (see box).

But for other riding horses—even performance horses—providing a salt block for voluntary consumption is typically adequate.

Assistant Teaching Professor
Equine Ambulatory
and Internal Medicine
College of Veterinary Medicine
University of Missouri


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