Fast facts on salt and what horses need


Nutritionist Juliet Getty shares her tips on supplementing horses with salt.

Regardless of the weather, horses require a daily supply of salt. In cold seasons, salt helps promote enough water consumption to prevent dehydration. In warm seasons, salt replaces what is lost from perspiration.

Heat, humidity, and exercise increase the horse’s need, but a full-sized horse requires at least one ounce (two level tablespoons or 30 ml) of salt each day for maintenance. This much provides 12 grams of sodium.  Hot, humid weather calls for at least two ounces per day.

» Salt for horses: An important balancing act

The best ways to ensure your horse gets enough sodium include offering free-choice granulated salt, or adding salt to your horse’s meal (for palatability, limit the amount to no more than 1 tablespoon per meal). A salt block should be available should your horse want more. A plain, white salt block is preferable, but many horses do not lick it adequately since it can be irritating to the tongue. Mineralized blocks often go untouched due to their bitter taste; however a Himalayan salt block is often preferred.

Calculate the amount of sodium your horse is getting from any commercial feeds or supplements and add salt accordingly. Always have fresh water nearby.

A feed balancer will add minerals and nutrients to a horse's diet.


A full-sized horse does best on a diet that offers 1 to 6 mg of iodine each day to keep his thyroid gland working properly.

Because the iodine content of grass is too low to measure, it is best to rely on supplementation – from salt or other sources – to meet your horse’s need. Many supplements and fortified feeds already add it. It’s always best to know what your horse is consuming since too much iodine can damage the thyroid gland.

Since all full-sized horses require at least one ounce (2 tablespoons) of salt per day for maintenance (and up to 3 ounces/day when perspiring heavily), iodized salt is a good way to add iodine and provide the needed salt as well. Granulated salt that you buy in the grocery store comes in both non-iodized and iodized versions; one teaspoon of iodized table salt contains 0.4 mg of iodine (3 tsp = 1 Tablespoon = 15 ml).

White and brown salt blocks generally do not contain iodine, whereas blue and red ones do. Sea salt, kelp, and other natural salt sources can vary tremendously in their iodine content. Only use reputable sources that guarantee their iodine analysis in writing.

Hot work: a special protein in horse sweat called latherin acts by wetting the hairs to facilitate water flow for evaporation. The side effect of this is lathering, which is often seen on the coats of sweating horses, especially where rubbing occurs.


Your horse sweats more during the summer, making electrolyte supplementation worth considering. But electrolytes alone will not protect against dehydration. Your horse needs to have enough sodium (salt), especially if he is in work of any kind.

One way to accomplish this: provide a plain, white salt block, Redmond salt rock, or Himalayan salt rock in close proximity. But make sure your horse licks it; many horses do not. Even better is to offer coarsely granulated salt free choice by pouring some in a small bucket. You can also add salt to each meal.

Be aware that electrolyte supplements should be given only to a horse that is already in good sodium balance.

Electrolytes are designed to replace what is lost from perspiration and should contain at least 13 grams of chloride, 6 grams of sodium, and 5 grams of potassium per dose. If your horse works more than two hours at a time, provide a dose of electrolytes after exercise by adding it to a gallon of water, top-dressing a feed, or offered via syringe. And always, be sure to keep fresh, clean water nearby.



Juliet M Getty

Juliet M. Getty, Ph.D. has been called a "pioneer in free choice forage feeding," and her articles and interviews often appear in national and international publications. » Read Juliet's profile

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