Written by Stephanie Davis, DVM 

Winter is finally (and unfortunately) here, and it is important to keep your horse well hydrated (for many reasons) but particularly to prevent dehydration and possible impaction colics. Horses tend to have impaction colics more often in the winter season because cold water is less inviting when it is FREEZING outside.  So, we need to monitor what they drink more closely during the winter months. The average horse should drink somewhere between 6.5 and 9 gallons of water a day. If you notice that your horse is not drinking a sufficient amount, there are a few tricks that you can use to keep them healthy and hydrated.

First and foremost, a horse should have access to as much CLEAN water as he could possibly drink at all times. So, even though the worst job in the barn in the winter is dumping and scrubbing those buckets, it is very important! 

Research has shown that horses will drink more water if it is warm or tepid. So, water heaters may be needed if you have a horse that is not a good drinker.  Some horses may also prefer flavored water. You can add some apple juice to one bucket to encourage them to drink. 

It is also important to remember that dehydration cannot be detected until they have already lost 5% of their body weight. So, if your horse weighs 1,000 pounds, you will not see outward signs of dehydration (skin tenting, sunken eyes, fatigue, etc…) until he has lost 50 pounds of fluid. That is a lot! So, in this instance, PREVENTION is the key to success.

Everyone knows the old saying that you can lead a horse to water but you can’t make him drink. There is an actual reason for that! The brain trigger for “thirst” happens when there is either low blood volume or high Na (sodium) in the blood. Well, horses get their “thirst” trigger slower than humans because of the difference in our sweat. When people sweat, we don’t lose very much sodium. So, when we lose other electrolytes and water in sweat, the sodium left in the blood is high. This tells our brain to drink. Well, our horses are not very efficient at keeping sodium and will lose more in sweat than we do. So, even though they have lost the same amount of fluid and other electrolytes, the concentration of sodium in the blood may still be low and the brain doesn’t know that the horse needs to drink yet. So, even though WE know that our horse needs water, his brain may not know it.

So, we know how important it is to keep our horses hydrated. What can we do? One option for getting more fluid in the horse is to get more water in their feed.

You can add water to any concentrate that is fed. This is only a small volume of water, but every little bit can help. So, if you add water to your concentrate, you can also add water to your hay. The very best way to do this is by steaming the hay. When the hay is steamed, the plant will absorb some of that water. A steamed bale will be almost 5 to 7 pounds heavier compared to when the hay was dry. So, there is a considerable amount of moisture that is added to the hay when steamed. 

Another option is to give electrolytes particularly after strenuous exercise. There are many electrolyte pastes and powders on the market.  If you do put the electrolytes in the water instead of the feed, be sure the horse has another fresh bucket of plain water. Steaming hay, along with watering grain, keeping water buckets full and clean, and adding electrolytes (when necessary) are a great way of keeping your horse hydrated and healthy.