How much water should my horse drink?

Short answer

Clean, fresh water should be available at all times. A 500 kg (1,100 lb) horse typically drinks 5–10 gallons (20–40 liters) per day, but intake can rise to 15+ gallons in heat, during work, or on dry hay. By establishing a baseline of water intake for your horse, you can monitor their water intake variations more accurately.

Real-Life Example

In wintertime many of us know the struggle of keeping water troughs from freezing. Horses can tend to drink less when water is ice-cold or partially frozen over, so monitoring the water levels is important. When they’re eating dry hay and supplemented with salt, there is an increased risk of dehydration which may lead to gut issues or colic episodes.

It Depends

Water needs change with:

• Temperature - Hot conditions may increase water intake and cold conditions may decrease
• Workload and sweat loss may increase water intake
• Salt intake may increase water intake
• Lactation may increase water intake
• Dry hay may increase water intake, and pasture may decrease water intake
• Travel and stress could decrease water intake

When to Seek Guidance

Contact your veterinarian if you notice:

• Reduced manure output
• Dry, firm manure
• Lethargy
• Skin tenting (dehydration)
• Colic signs

With your baseline established already, it’ll be easier to share their current consumption along with any other conditions you notice.

---

Sources:
Merck Veterinary Manual – Water Requirements in Horses

American Association of Equine Practitioners - Care Guidelines (AAEP)

National Research Council. (2007). Nutrient Requirements of Horses (6th ed.).

Michigan State University Extension – Horse Water Needs