Pass the Salt: What to Know About Sodium

Here’s the how and why.

Flickr/Kate Brady/CC

Doctors tell us that as humans we should avoid excess salt in our diets. Why then do horses seem to need salt?

Salt is a mineral composed of sodium and chloride (chemical formula NaCl). Horses need at least 10 grams (about two tablespoons) of sodium a day, through salt. Increased activity and hotter temperatures can call for a double in the minimum requirement.

Why do horses need sodium?

Sodium is one of the main electrolytes found in the blood and fluid surrounding the cells. If the sodium levels get too low, blood can’t hold enough water. When that happens, the adrenal glands releases the hormone aldosterone, which then tells the kidneys to not excrete any sodium to leave the body. When the kidneys don’t release sodium, they instead release potassium in its place, which creates an electrolyte imbalance.

Low levels of sodium can cause all different conditions: tying up, anhydrosis (lack of sweating) and a rapid heart rate.

Horses with HYPP (Hyperkalemic Periodic Paralysis), which can be found in some halter horses that are descendants of the stallion Impressive, also have to really watch their electrolyte balance. HYPP is an inherited genetic defect that affects muscle function. HYPP also can occur in humans. The condition interferes with a protein that disrupts the natural opening and closing of a sodium ion channel in the membrane of muscle cells: basically the cells get flooded with potassium, which causes uncontrolled muscle twitching, weakness, and periodic paralysis found throughout the body. Attacks can be mild to severe.

In some mild attacks, the horse will act like he’s tying up or colicking. Severe attacks look like the horse is having a seizure, and some attacks can even cause death. Salt and water are especially important for these horses, since a lack of salt or water reduces urination, which is how the horse is able to excrete the excess potassium.

Salt also helps the encourage the horse to drink in colder months which can prevent an impaction colic. If your horse isn’t drinking, just sprinkle some loose salt on top of his feed.

What about electrolytes?

Electrolytes are helpful if your horse is in heavy work and sweating out more than he consumes, especially on really hot days. You DO need to be very careful feeding electrolytes, because they can harm your horse more than they can help your horse if he or she has HYPP or already has an electrolyte imbalance. Electrolytes can cause an excess build-up of potassium — refer to the above paragraphs about the consequences. Electrolytes are also not a substitute for feeding salt, since the salt found in electrolytes is not enough to balance all the other minerals. Your best bet is to contact your vet before feeding them.

White salt blocks vs red mineral blocks

White salt blocks are safe for both horses and cattle. Red mineral blocks tend to be made for either horses, or cattle, but not suitable for both. So a red mineral block for cattle will not provide the correct minerals for horses, and a red mineral block for horses will not provide the correct minerals for cattle.

It is advised to put out both a red horse mineral block and a white salt block, so the horse has both options. Mineral blocks with molasses are discouraged because the horse can bite off chunks at a time, getting way more minerals than needed and wasting your money.

Some people also sprinkle loose table salt on their horses’ feed, on top of giving their horses salt and mineral blocks to make sure they’re getting enough salt in their diet.

Is your horse salt deficient?

Inadequate salt in a horse’s diet can result in behaviors such as chewing objects that have salt on them, chewing wood, licking dirt and sand, chewing manes and tails and licking other horses who are sweaty.

Unless a horse has been salt-starved, they will normally not over-consume salt. For ones that are salt-deprived, they will consume salt in excess for a few days, until their body is balanced again. Make sure they always have an adequate supply of water.

Horses need salt, while humans need to watch their salt intake. Excess salt in humans can cause high blood pressure, which can result in heart disease or stroke. Humans and horses have different types of hearts: horses do not suffer from the same heart diseases that humans do, and rarely ever die of a heart attack. They suffer from other conditions such as leaky valve disease and atrial fibrillation, which we will cover in another article.

So, save that extra salt and sprinkle it on your horse’s feed instead of your french fries.

References:

Feeding the HYPP Horse: Southern States

The Importance of Salt: Discover Horses via Equisearch

Salt for Horses: Champions Choice