Horses are not unlike people, in that they too enjoy fresh, clean water. Not only will it keep your horse content, it will help keep away many easily preventable sicknesses, too. Colic is one example. According to About.com's Katherine Blocksdorf, here are some basic ideas concerning water for your horse.

How much?

The amount of water that your horse needs depends on a lot of factors:

• Size
• Climate and temperature
• Type of feed currently used (more water for dryer food)
• Level of you horse's activity
• Pregnancy

Keep it clean
Keeping clean water is extremely important for preventing dehydration. Things such as bugs, leaves or other debris can easily get into your horse’s water supply. Be sure to refill the water daily and thoroughly clean out the trough weekly. It won’t take much for some nasty stuff to start growing in there, especially in the summer.

Beware the winter
If you are in a climate that includes icy winters, keeping your water defrosted is a huge concern. Buckets and troughs with heaters are highly recommended. Keep in mind that sometimes horses still won’t consume enough water, because though it’s not frozen, it still may be too cold.

Source: About.com