Newsdate: Monday 14 October 2019 – 7:00 am
Location: FLINT HILL, Virginia

Water is the number one nutrient fed to any animal, and it is the most often overlooked nutrient in any species’ nutritional program. By weight, horses consume two to three times as much water as food.

Horse drinking from water trough

Factors in how much water a horse needs include: environmental temperature, humidity, feed quality, type and amount of feed, physical activity level and health.
© 2008 by Gwendolyn Sams

If the water contains toxins, high levels of minerals or any other unbalanced agent, nutritional problems can result. The media has often reported that water quality throughout the world is suspect -- even well and spring water in the countryside far from polluted cities. Bottled water quality may also be suspect, as there have been reports of contamination of municipal water being bottled as spring water.

Horses should consume enough water to replace what is lost through feces, urine and sweat. Consumption depends on several variable factors. These factors include: environmental temperature and humidity, feed quality, type and amount of feed, physical activity level and health.

An average amount would be approximately one gallon (3.78 liters) of water per 100 pounds (45 kg) body weight per day. A 1,100-pound (500 kg) horse’s base level might be to drink about 11 gallons (42 liters) of water per day in normal, average weather conditions. The same horse training hard for a Three-Day Event could consume about 33 gallons (125 liters) of water per day.

Mares in lactation can increase their water consumption about 50 to 80 percent for milk production.

In all horses, but most importantly in the performance horse, the amount of water required per day is dependent on the amount lost through sweat during exercise. Sweating is an important function in maintaining the core temperature of the horse. Horses can lose up to three gallons (12 liters) of sweat per hour.

Therefore, that same Thoroughbred competing in the Three-Day Event would require more water after completing the cross-country course than it would after the dressage test because it worked harder for a longer period of time, causing it to sweat more.

Temperature and humidity will also affect water loss from the horse. Horses generally drink more and eat less when the temperature is high. In an environment with high relative humidity (over 80 percent), sweating does not efficiently cool the horse, so it is at a risk for overheating.

Water Problems

Many horses live in urban areas, with urban water supplies. Some stables give horses water they will not allow people to drink. People are drinking more bottled water than ever; however, it is not practical to do that for horses. Water filters can be added to a barn, but if it is a boarding barn it may not be practical.

Many systems to filter water are expensive when looking at the volume of water used by a large commercial barn. Filters of many sorts can be used, from simple charcoal filters attached to the hose, to complex systems attached to the main water intake for the farm.

Herbicides and pesticides are designed to throw the plant or insect out of balance. A quart or so will often treat many acres of land after it has been diluted. The waterways and aquifers have become large vats for these diluted combinations of herbicides and pesticides mixed together and yet nothing is known about the effects of these chemicals in combination.

Chloride is an important nutrient that has been identified as being in excess in much of the water supply, and most certainly in urban chlorinated sources. Chloride is chemically the same as chlorine, the chemical used to sterilize or clean water when there is excessive bacterial growth.

Evidence is mounting that chlorinated water is toxic and may contribute to or cause cancer in people. This data is not available for horses yet; however, there is every reason to expect similar potential illnesses or negative health effects.

Drugs are also present in water supplies, and not just in urban areas. No research has been done on the cumulative effects of the low levels of many types of drugs found in the water supplies. But there are well-documented changes in aquatic life, such as sterility in individuals, deformed fish and amphibians and others.

Water consumption is influenced by taste, which is often determined by mineral content, in particular by chlorine, potassium and sodium. The animal tries to maintain an internal balance and minerals affect physiologic function.  Water intake is decreased if the minerals are getting out of balance.

Water can have an excess of a particular mineral or ingredient such as nitrates, iron or copper. Nitrates can affect vitamin A and selenium absorption. Without vitamin A, the body cannot use vitamin D, E or the full B complex vitamins.

High iron in the water has an indirect effect on calcium and phosphorous. This occurs because phosphorous is the closest to iron in atomic weight. High iron impedes the utilization of phosphorous, which in turn affects the availability of calcium.

However, it is not a calcium deficiency; it is a phosphorus and iron problem. Sometimes the mineral content of water is seen as a precipitate (white, green or other colored deposit).

The best way to manage the potability of the water source is to test for toxins, high levels of minerals and chloride and bacteria. This can be done through standard water analysis. Many other tests are available: however, it is best to know what you want to test for, since many tests are expensive.

Solutions for Water Quality Issues

Since it may not be possible to correct water quality issues, you can feed and supplement with high quality products to help detoxify and support the horse. Clays such as bentonite absorb toxins in the gut. The clay can be fed at the rate of about one ounce per day, mixed with feed or water. Diatomaceous earth can also be fed to help pull toxins from the body. I use the organic product