A 1,000- to 1,100-lb. horse eating at least 2% of his body weight in hay/day (22 lbs.) will need to drink between five and eight gallons of water/day. While summer brings fresh grass, which is 80% water, winter simply brings frozen/freezing water, which is a deterrent to adequate water consumption. Insufficient drinking is the leading cause of colic and choke in winter.
Water should also be located in close proximity to feeding and shelter areas and care taken to make sure the area doesn’t become surrounded by ice. You can help minimize risk of dehydration if you:
• Keep water cleared of ice.
• Don’t expect horses to consume snow for water.
• If possible, provide warmed water at least twice a day.
• Provide water at the same time as, or within an hour after, feeding hay, as eating hay stimulates drinking).
• Add 1 oz. (two tablespoons) of table salt to feed daily.
• Incorporate soaked cubes, pellets or mashes into the winter diet; the more water the better.
If hot water isn’t available at the barn, you can soak the meals at home in a bucket or 20-gallon recycled supplement container or restaurant-size food bucket. If you start with hot water, temperatures inside enclosed but unheated areas will usually be high enough to prevent freezing but low enough to prevent spoilage even if left to soak for eight hours.