Water for Your Horse

How Much and How to Supply It

Horse drinking from a water trough
Water troughs should be kept clean. Image Credit: vaderbreath / Getty Images

A constant supply of clean fresh water for your horse is an essential element in good horse care. Your horse should always have drinking water available in its stable and pasture. While traveling, dehydration is a concern, and on long trailer rides and during events or long trail rides, horses must be offered water frequently. 

How Much Water Does a Horse Need?

The needs of individual horses will differ greatly. Things that affect the amount of water a horse needs are:

  • Air Temperature
  • Workload
  • Feed (grass vs dry fodder)  
  • Pregnant or nursing mare
  • Size
  • Health

Fresh clean water should be available to horses and ponies at all times. Insufficient water can contribute to poor health. Chronic dehydration can cause a horse to lose weight and be in poor condition. Dehydration can be deadly. Lack of water can cause impactions leading to colic, especially during the winter months, when a horse's diet may consist almost solely of dry hay. Unhygenic water and watering equipment such as troughs and buckets can also harbor bacteria or viruses that can make your horse sick.

Expect horses to drink more when they are working hard and sweating, in hot weather, and when from changing from a from pasture grass to hay. 

How Can I Supply Water?

Buckets or automatic waterers can be used in stables. Automatic waterers are convenient, but it is difficult to monitor how much water your horse is drinking should you need to. Some horses won't know how to use them at first, or some won't like them because of the noise some waterers make. It may take awhile and some encouragement to teach your horse to drink from an automatic waterer.  Buckets are easier to clean, but heavier to carry. They can spill unless safely secured, leaving wet messes in their stalls and aisle ways.

If you live in an area where the water supply can freeze up, you'll need to take extra care to make sure your horse is getting enough water during the winter months. A horse cannot eat enough snow to provide adequate water. Because they are not eating moisture from pasture grass, dehydration and impaction colic is more possible.

In the pasture, you may be able to rely on a natural water source such as a spring-fed pond, or stream. Alternative water sources will be needed during freezing weather. The banks of ponds and streams should be safe for horses to get to the water. If the bank becomes too slippery, the horses may not be able to safely approach or get out of the water. Unsafe water sources should be fenced off. Because the water quality of open and natural water can change, it’s important to check it frequently. Heavy rains, spring runoff, and other factors can affect water quality and accessibility. A horse may not know the difference between safe and unsafe water.

Automatic systems, whether they are indoors or out should be checked daily to be sure they are functioning, and that they are not soiled. It’s not unusual for horses to leave manure in buckets and waterers, and dust, algae, and other contaminants can cloud the water. Cords of heated water buckets and trough heaters should be checked and secured so curious horses cannot play with them. Both heated buckets and heaters should be plugged into a properly wired GIFC.

How do I Keep the Water Supply Fresh?

Troughs or automatic waterers can be used outdoors. Troughs and waterers will need to be cleaned and refilled regularly. Leaves, chaff, insects, and other debris should be cleared out daily. Containers can be scrubbed out with a bristle brush and vinegar, then rinsed well. The frequency will depend on how clean the water stays and how quickly the algae grows. You may need to clean your trough at least once a week during the hot summer months and less frequently during the colder weather. In sunny summer weather, algae growth can be a problem, And, standing water can harbor mosquito larvae.

Again, water quality in natural sources may not be consistently safe and should be monitored. Your local health unit or agricultural extension should be able to advise you on how to test the water for safety.

Approximate Water Consumption By Horse Weight

Body Weight Minimum Average Maximum
900 lbs/410 kg 3 gal/ 13.5 l 4.5 gal/ 20 l 6 gal/ 27 l
1200 lbs/545 kg 4 gal/ 18 l 6 gal/ 27 l 8 gal/ 36 l
1500 lbs/680 kg 5 gal/ 22.5 l 8 gal/ 36 l 10 gal/ 45 l

Chart from Recommended Code of Practice for the Care and Handling of Farm Animals - Horses, Canadian Agri-Food Research Council, 1998