Provide free access to clean fresh water at all times” is the advice given by most horse management or equine nutrition books. The simplicity and brevity of this statement fails to reveal the complexity and importance of water in equine nutrition. Water is the most important nutrient and it is too often overlooked in a horse’s diet. Deprived of all nutrients except for water, horses can survive for 20 to 25 days. Deprived of water but not feed, horses will only survive 5 to 6 days at best. More importantly, within two days, horses will refuse to eat and show signs of colic, which can result in an even earlier demise.
Approaching winter and especially when winter is in full swing, horses tend to reduce their water intake. This reduced water intake in addition to an increase in dry hay consumption can lead to a greater incidence of impaction and colic. Horses may eat snow to obtain needed moisture, but putting cold snow into a cold animal will never meet its needs; not only that, it will increase the energy needed to maintain body temperature. Do NOT rely on snow to provide your horse with the water it needs.
Horses require between 8 and 10 gallons of water per day. Remember that cold water and ice will reduce the amount of water most horses drink. Water consumption is most easily measured when horses are watered in buckets in their stall. If buckets are used, offer enough water so that the horse has access to more than the minimal 8 to 10 gallons per day, add buckets if necessary. Try to maintain water intake above the minimal amount. Interestingly, a study of water consumption during cold weather has indicated warming the water to well above freezing, around 90 degrees, increased water consumption roughly 40 percent. An easy way to accomplish this is to bring a half bucket of hot water and mix it to the desired temperature. Even if all horses will definitely benefit from this practice, it’s probably not necessary to warm the water for all of your horses. Those who are not drinking enough, elderly horses and those with a history of impaction should receive warm water if you want to avoid dehydration that could lead to impaction colic or choking.
The addition of salt to the diet will also increase water consumption. Most horses will do well with free choice salt in either block or loose form. It is dangerous to force a horse to consume salt unless there is free access to clean water. The preferable type of salt is the plain white one, which is a 100% sodium chloride.
With the right tools, salt and warm water, it is possible to lead your horse to water and make him drink! Remember though, winter or summer, the rule is the same: if you wouldn’t drink the water, don’t expect your horse to drink it.
Purina Equine Nutrition Team