Horses must have access to clean drinking water 24 hours a day. An average horse will consume at least a half a gallon of water for every 100lbs of body weight. The demand increases with high temperatures and humidity, increased level of work and sweat output, less digestible feeds, and during lactation. A horse in regular, heavy exercise, particularly in hot weather, will consume as much as 16 gallons of water daily. A mare nursing a foal will consume 50%-70% more water than an average horse. Horses fed coarse hay or pasture will double their water intake over those fed a digestible grain ration with good quality hay and pasture.
A lack of water will cause a horse to reduce its feed intake and growth rate, and leads to dehydration. Insufficient water supply can also cause impaction colic as the food in the intestine dries out and digestion slows. Dehydration reaches a critical level when it is visually evident by reduced elasticity of the skin (try pinching the skin on the neck to see if bounces back), a glazed appearance of the eye and lethargy.
Good horse management is reflected by free access to clean, cool water at all times. Good business management is reflected by providing this to horses with a minimum amount of labour. Automatic waterers, particularly those that monitor water consumption, are well worth considering. The initial cost is soon recovered by productive horses and reduced overhead.
Article courtesy of the Equine Research Centre
Guelph, Ontario, Canada