Keeping Horses Hydrated

By Cat McKeen

There’s a reason for the proverb, “You can lead a horse to water, but you can’t make him drink.” The most important nutrient in a horse’s diet is clean, fresh water. A horse can go several weeks without food, but since a horse’s body is made up of 65 – 75% water, it can only go a few days without water. And this time of year is critical for your horse’s water intake. Along with the heat and humidity, many horses are participating in summer shows, so they need more water than usual. This week’s blog post will provide a few tips on how to keep horses hydrated, as well as some of the warning signs of dehydration.

How Much Water Does a Horse Need?

Depending upon a horses exercise level, the demand for water can be over 25 gallons of water a day and, as they produce up to 3 gallons of milk a day, lactating mares also need a larger than normal supply of clean water. Most horses need a minimum of 10 gallons a day and, as a horse’s stomach is relatively small for its size (holding only 8-10 gallons), horses should have access to clean water at all times so that they are not at risk of dehydration.

Dehydration can cause poor blood flow in the gut resulting in increased chance of colic. One of the ways to tell if a horse is dehydrated is the pinch test. Using your fingers, lightly pinch and pull the skin in the middle of a horse’s neck. If the skin immediately flattens back out, the horse is hydrated. If it takes1-2 seconds, it is mildly dehydrated, and if it takes 10-15 seconds, the horse is severely dehydrated. At this point, you should call your vet.

How Dehydration Affects Horses

A horse’s muscles are 75% water. As little as 2% dehydration will effect a horse’s performance, and as dehydration increases through exercise, stress, traveling, hot and humid weather, and other factors, more water will be pulled from the digestive system and to keep the horse’s temperature down. This can affect digestion and cause problems in the GI tract.

Sweating can be a problem as well if the fluids aren’t replaced. Just like humans, horses sweat to keep their body temperature down. This fluid needs to be replenished not just with water, but with the minerals in salts. Horses also need access to a salt source of some type. Salt blocks or salt licks are affordable and popular among horse owners, but research has shown that the salt intake from salt licks can be variable. In addition, horses may not consume enough salt from these sources to replenish the minerals in the body. Table salt is another convenient and inexpensive way to supplement sodium intake.

Other Signs of Dehydration: