How to keep horses (particularly picky ones) hydrated at and away from home
A mature horse’s body is approximately 70% water. This fact underscores just how important it is that all horses, regardless of age or classification, have a consistent source of clean, fresh water to drink at all times.
“There are a multitude of variables to take into consideration when we think about how much water our horses should be consuming daily,” says Amy Parker, MS, PAS, equine nutritionist and manager of technical services at McCauley Bros, in Versailles, Kentucky. “Water intake will depend upon the dry matter content of the diet, the horse’s activity level, and the environmental temperature.”
Normally, horses consume 1 gallon of water daily per 100 pounds of body weight (at environmental temperatures of 60-70 degrees F). Horses at a healthy body weight need to consume 2% of body weight in forage per day. So, a 1,000-pound horse eating the necessary 20 pounds of hay must drink an average of 9 to 10 gallons of water per day—about 2 quarts per pound of dry matter consumed. What your horse eats influences his water intake, says Parker. Horses eating diets high in dry matter such as hay consume more water than horses grazing good pasture all day. This is because as dry matter intake increases, the body needs additional water to maintain normal gastrointestinal (GI) tract function and saliva production. Water intake provides the horse with proper moisture to digest and transport feedstuff through the GI tract.
In contrast, “fresh forage pastures may contain as much as 90% moisture,” she says. “Therefore, horses will have lower water consumption because they are receiving that water from the grasses they are consuming.”
A horse’s water intake increases as the environmental temperature rises. When you add exercise, your horse might drink upward of 20 gallons of water per day, depending upon the intensity and duration of the exercise. Water requirements don’t necessarily decrease during cold weather, says Parker, but, rather, increase as horses consume more dry matter.
How To Keep Your Horse Drinking
Just because your horse has access to water does not guarantee he’s drinking enough to stay hydrated. Parker says horses prefer drinking water temperatures ranging from 45 to 65 degrees F. Although horses will consume water at temperatures outside that range, they prefer a more moderate water temperature.
Whether your horse’s water source is a tank, bucket, or automatic waterer, clean it at least once a week to discourage mosquito breeding and bacteria and algae growth. Never place a water source where it will be exposed to direct sunlight. This also applies to water hoses or pipes leading to the source. The sun can heat the waterline to the point the water coming out of it is too hot to drink. Water temperature in excess of 85 degrees F is not uncommon in water sources on extremely hot days. In colder climates bury the waterline 3 to 5 feet below ground surface to ensure it does not freeze.
Because the average adult horse has a drinking speed of 3.5 to 7 liters per minute, Parker recommends using automatic watering or refill systems that fill at a rate that allows the horse to drink to his content without emptying the vessel.
“Dehydration can occur in horses that have access to automatic watering systems with slow rates of fill,” she notes. “Horses are not going to wait around for the water to refill.”
Knowing how much horses are drinking via automatic waterers can be difficult. Many companies offer meters you can add to help monitor consumption. Parker also warns that some horses, such as those wearing grazing muzzles, might have trouble using waterers. Troughs are better choices for these horses.
“Using ponds or streams as a water source is not advised,” says Parker. They can develop dangerous algae, particularly in the warmer seasons, and be contaminated by harmful pesticide and herbicide runoff. Additionally, banks can freeze and sharp ice edges can materialize around bodies of water during winter. If a natural water source is far from the horses’ feed source, adds Parker, they might not drink as often as they need to.
In winter encourage your horse to drink by offering warm water. This is especially important with senior horses. Parker says older horses (20+) might become more sensitive to cold water (32-38 degrees F) and drink less volume than if they have warmer water (45-65 degrees F) during cold weather. Researchers have shown that horses preferentially drink warm water when the weather is cold and can consume a substantial amount of their daily water requirements within the first 60 minutes of being offered a fresh bucket of warm water. Horses show no drinking preference for cool or warm water during hot summer weather.
Using Salt to Stay Hydrated
Because sodium helps stimulate thirst, horses must maintain adequate amounts in their blood. Of the minerals required in the horse’s diet, salt (sodium chloride, NaCl) is the only one horses can self-regulate. Parker says providing free access to salt helps trigger a thirst response and can keep horses hydrated year-round. You can provide salt loose in your horse’s feed (1 ounce twice daily) or as a salt block in the stall or pasture. Some horses prefer one form (loose vs. blocks) over another.
Offering a horse salted water immediately after exercise can encourage him to drink. Shannon Pratt-Phillips, PhD, professor of equine nutrition and physiology at North Carolina State University, in Raleigh, says consuming slightly salty water (1 ounce of table salt per 5 gallons of water) after exercise results in increased sodium in the bloodstream and, so, stimulates the horse’s thirst center. As a result, the horse drinks more than if consuming nonsalty water. Following the initial salty drink, offer plain water. Both Parker and Pratt-Phillips agree that if a horse is thirsty post-exercise, let him drink.
Consider offering electrolytes to horses in regular work. Electrolytes are the body salts that play essential roles in all body cells and are involved in all biomechanical functions. When properly balanced, they help encourage drinking and replenish the electrolytes lost in sweat.
Be sure the electrolyte is balanced to mimic equine sweat; unbalanced electrolytes can result in mineral imbalances, delay exercise recovery, and might not encourage rehydration (therefore increasing dehydration risk). Parker suggests administering electrolytes every time the horse sweats. Feed a well-formulated and concentrated electrolyte as directed by the manufacturer. When buying electrolytes, make sure the first ingredient is not sugar. If it is, the electrolyte levels will not be high enough to have a meaningful effect.
Pratt-Phillips says you can make your own electrolyte by mixing sodium chloride (table salt) and potassium chloride (“lite” salt) in a 2:1 ratio and offering it with your horse’s usual grain mix. Note that horses with hyperkalemic periodic paralysis (HYPP, a genetic muscle disorder) should not receive potassium supplementation. Offer plain salt or electrolytes formulated for HYPP horses instead.
Hydration Challenges on the Road
One challenge many owners have is making sure their horses drink when traveling. Horses can be finicky about unfamiliar water sources, due to different tastes and smells, resulting in either a reluctance to drink or drinking less.
You can use several tactics to get your horse to drink when traveling. One is to bring water from home to an event, show, or trail ride. Because this strategy might not always be practical, another option is to mask the water’s taste or smell by adding a flavored electrolyte, human drink mix such as Kool-Aid (without added sugar), Gatorade, apple juice, peppermints, or molasses/syrup. If you go this route, start training your horse to drink flavored water at least 10 days to two weeks before the event, says Parker. Experiment with flavors to find your horse’s preference.
You can also encourage water intake by soaking hay. Unlike soaking hay to remove soluble sugars, doing so to increase fluid intake involves placing the hay in tepid water for only a few minutes prior to offering it to your horse. For horses not accustomed to eating wet hay, you might have to start with small amounts and increase the ration as the horse adjusts to consuming it. Again, practice this well in advance of leaving for your destination. Uneaten damp hay can start to spoil, so be sure to discard it promptly.
Other ways to encourage water intake include adding water to a grain meal; adding a handful of grain to a water bucket; or feeding water-soaked hay pellets or cubes. Note that if you’re putting grain into your horse’s water bucket, you’ll need to empty and clean that bucket more regularly. Always have a second water source available with nothing added to it.
Keeping horses hydrated is not exceedingly difficult, but it can be frustrating and concerning for the owner of the reluctant equine drinker. Understanding what stimulates thirst and how to increase consumption or create circumstances under which the horse will continue to drink is what’s important.