Water, the most important feed for a horse

A horse can drink between 25 and 75 litres of water a day, depending on the climate, its physical activity, the type of feed and the amount of moisture the feed contains.

These different criteria must be taken into consideration… 


A horse at grass drinks relatively little water : between10 to 20 litres depending on the season, as grass contains a great deal of water. On the other hand, horses in the stable with manufactured feed and dry forage will need much more water. 

A horse will not drink dirty or polluted water. If a it does not drink enough the risk of colic is increased. Dung should be checked to ensure it is not hard and dry. 

If horses drink from buckets, these should be washed every day. 500 litre tanks should be cleaned carefully with a brush, every two weeks. 

Nowadays, drinking troughs are often automatic but care should be taken to ensure they are working properly and are clean. 

For horses drinking from buckets, feed must be given after the horse has drunk to prevent possible stomach disorders. 

During winter, it is necessary to check that big tanks are not frozen and ice should be broken every day, if necessary. A piece of wood floating on the top of the water delays ice formation. 

It is better to keep horses in until late in the morning to stop them drinking ice cold water, a cause of colic. It is the same for frosted grass which can cause colic and abortion in mare in foal. 

Just wait until the sun has warmed the pasture before letting horses out. 

It is adviseable to have a bacteriological and chemical analysis to measure the presence of nitrates, nitrites and heavy metals when using water from a well. These analyses are not very expensive when compared to a visit from the vet! 

If your water comes from the tap, there’s nothing to stop you checking its quality. The water is probably good for you and your family, but after heavy rain it may contain high quantities of chlorine, not very appreciated by the intestinal flora of your horse. 

A water specialist can give valuable advice, and water filters (carbon…) could be installed. 

After sustained exercise, be careful to not give large quantities of water and especially not cold water to avoid “water colic”. It might also be useful to give a little salt in the water to compensate for mineral loss during sweating (10 litres per hour). A horse also needs a supply of electrolytes (sodium, potassium, chlorine) to help it recover rapidly from effort. 

Be careful! A dehydrated horse will not automatically drink. 

It’s not unusual for riders bring their own horse drinking water to Endurance trials. A horse is very choosy about the water it drinks, some may refuse to drink if the water has a strange taste. 

A lactating mare must be able to drink sufficient water to produce enough milk. A French riding horse mare produces between 15 and 18 litres of milk per day while a heavy horse mare can produce up to 25 litres a day. 

Yet another good reason to supervise quality as well as the quantity of this “most important” feed for horses : WATER.