Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter.
Daily water consumption varies quite a bit. Season of the year, workload, reproductive status, diet, and climate factor into the volume of water needed by a particular horse on a specific day. As a starting point, the average horse drinks between 5 and 10 gallons (19 and 38 liters) of water each day. The horse may need slightly less if it is grazing lush pasture because fresh grass contains a high percentage of liquid.
1 Horses drink less in cold weather, but insufficient water intake can lead to dehydration and colic, especially in older horses.  If your horse is soaked to the skin, shivering or his ears are cold, heâs chilled and stressed; he needs a dry shelter and perhaps a blanket.