If you could snap your fingers and remove all the water from your horse’s body, there wouldn’t be a whole lot left. The average adult horse’s body contains approximately 70% water. In other words, there are roughly 700 pounds of water in the average 1,000 lb. horse.
This makes it obvious just how important it is that your horse has a consistent source of fresh, clean water to drink at all times.
So, how much water should your horse drink each day? That depends on a number of variables.
An average 1,000 lb. horse can drink anywhere from five gallons a day to as much as 20 or more gallons. Just as with humans, weather is a big factor. Expect your horse’s water consumption to increase when it’s hot and/or humid, even if he isn’t working. Add exercise to the equation and your horse may drink considerably more, depending on the duration and intensity of his workout, and the weather conditions.
The horse’s diet also greatly influences his water intake. A horse whose only forage is hay will drink more water than a horse grazing good pasture.
“What your horse is eating has a lot to do with how much he’s drinking. The average horse on a predominately hay diet will drink much more water than a horse on summer pasture. Grass can be as much as 90% moisture, while hay may contain less than 10%,” notes Hal Schott DVM, PhD, Dipl. ACVIM, a professor in the Large Animal Clinical Sciences Department at Michigan State University.
One common sense way to determine if your horse is drinking enough water is to regularly check the appearance and consistency of his manure. If it’s hard and/or dry, you’ll want to take steps to encourage your horse to drink more.
Keep Him Drinking
Just because your horse has access to water doesn’t mean he won’t get dehydrated. His water source must be clean, cool and fresh; otherwise, he might not drink enough, even in hot weather.
Whatever the source — bucket, water tank or automatic waterer — it should be in the shade, never in direct sun. This also applies to the water pipe leading to it. In hot climates, the sun can heat the water line to the point that water coming out of it is too hot to drink.
Check all water sources daily (even if you have automatic waterers or refill systems), and clean them out at least every three days to discourage mosquito and algae growth. Ask yourself: Would I want to drink this water? If not, make the necessary changes so your answer can be “yes!”
An average 1,000 lb. horse can drink anywhere from five gallons a day to as much as 20 or more gallons.
Make sure your horse always has free access to salt (either loose or block), so he can consume what his body needs.
Adding salt directly to his feed ration can encourage him to drink more.
“You can just add one ounce of sodium chloride (table salt) to the concentrate (feed ration) twice a day,” says Schott, who has spent significant time researching fluid and electrolyte balance in exercising horses. “This will help replace sodium and chloride lost in sweat and will make some horses drink more.”
Water After Exercise
Encourage your horse to rehydrate after exercise by offering salted water as his first drink, followed by plain water a short while after.
Studies at Michigan State University proved that offering a saline solution as the initial drink after exercise resulted in a greater total fluid intake and recovery of body weight loss during the first hours of recovery after exercise, as compared to only offering plain water.
“Just add one ounce of table salt to a five-gallon bucket of water. Then offer plain water 20 to 30 minutes later,” says Schott. “This is really effective for horses on a long trail ride and when traveling, and gets more total fluid into the horse to better fight dehydration.”
If the horse is thirsty, let him drink.
“We did a study that found there is no need to limit the first drink (after exercise),” notes Schott. “We found that the initial drink is pretty much just three to five gallons, because the horse needs a few minutes for that water to empty out of the stomach. The good thing about horses is that they won’t overdrink.”
But don’t make that water cold. Additional studies at Michigan State University determined that most horses will voluntarily drink more within the first hour after exercising if the water is about 68 degrees Fahrenheit.
On the Road
Horses can be finicky when it comes to water, especially when traveling. They may be reluctant to drink, or will drink less than they should, if the water tastes or smells different from what they are accustomed to drinking at home.
For this reason, some horse owners carry water from home when traveling to a show, event or trail ride. Bringing water from home isn’t always convenient or possible, so another option is to get your horse used to drinking water that has been slightly flavored. Just be sure to do this long enough before the trip so that you know your horse will drink the flavored water. You definitely don’t want to try flavoring his water the first time when you’re on the road or away from home.
You can flavor water by adding a little Kool-Aid (use the envelope without added sugar since all you want is flavor), Gatorade, apple juice or molasses to the water. It doesn’t take much. You may have to experiment to find what your horse likes best. This way, you can add his “flavor of choice” to the water when you’re traveling so it tastes familiar, which will encourage him to drink.
Whenever you offer flavored water — whether at home or on the road — always offer a separate bucket of plain water. This way your horse has a choice and you won’t discourage water intake if he’s not in the mood for water that has been flavored.