March 21, 2018
By Leigh Ballard
A horse’s body is about 70% water; so for an average horse, that’s over 700 pounds of water! Keeping a horse hydrated is very important for keeping all his systems “flowing.” Water is the most important nutrient, without which no bodily system can function. Water maintains the body temperature (thermoregulation), lubricates joints, keeps the central nervous system operating, aids digestion, cleans the body of toxins, and does many other jobs.
An average sized horse (1,000 pounds) at maintenance level, doing no work and not under stress, will drink a bare minimum of 5 gallons of water per day. Temperature and weather conditions, whether a horse is in work, whether a horse is on pasture, are some of the factors which can quadruple the minimum amount of water the horse might need – 20 gallons.
For healthy horse keeping, you should provide conditions to ensure that a horse always drinks enough water. Water should be as clean and fresh as possible; otherwise a horse might not find it agreeable and not drink enough. Water temperature can be a factor in a horse’s opinion of water. Water in troughs can become quite hot in the burning summer sun, and icy water in the winter is not inviting either. Water should be replaced or refreshed often. Water in buckets in stalls can become “stale” so that horses do not willingly drink it. Fresh water should always replace old water when a horse is put into the barn.
A horse should always have access to a salt block because providing plenty of salt keeps a horse drinking. A correct sodium balance causes the proper thirst response. To ensure that a horse drinks, a tablespoon of white salt top-dressed over the feed ration twice daily will generally keep a horse drinking enough for normal purposes. This practice is especially useful, for example, if a horse is on a dry diet of hay and you want to be sure the horse drinks enough to have sufficient moisture in the diet. Impaction colic can be caused by insufficient moisture in the diet. Horses on hay or hay cubes should drink significantly more than a horse pastured on moist grass, because the pastured horse takes in a great deal of water when grazing. Water significantly helps digestion, so in the winter when horses generally drink less, there tends to be higher risk for digestive upset or colic.
There are special occasions when one might worry more than normal about water intake. Travel is one of these occasions. Horses are notorious for being led to water and not drinking it! Who would want to drink strange tasting or “foreign” water? Transport stress is a cause of dehydration, so drinking water while traveling is important because trailers can get quite warm. The horse can lose water from sweating, either from warmth or nervousness. Traveling horses should be offered water about every three hours. Likewise, horse shows are another occasion where a horse might be picky about his water. What about horses standing tied to the trailer waiting for his turn in the show ring? Or how about the barrel horse that loses much water through sweat and hard work at a summertime show? All of these scenarios demand giving some special attention to water.
Ensuring that traveling or showing horses drink might take some creativity. Frequently offering water is the first line of defense. Soaked hay is another way to provide extra water. Flavoring the water or bringing water from home are other options. A horse can be accustomed at home to drinking water with flavoring, so using the same flavoring away from home tricks him into drinking foreign water. Besides flavors like Gatorade or apple juice, there are certain sweet feeds which flavor water quite well. There are also products on the market like Horse Quencher, which just about any horse will gulp after the first try.
Health conditions are also occasions which call for special attention to water. The pregnant or lactating mare needs much more fluid during pregnancy, for amniotic fluid and for the developing foal’s systems since the mare is “drinking for two.” During lactation, additional water is needed for milk production. Pregnant or lactating mares might need three times as much water as other horses in an equal environment. Illnesses, especially those involving diarrhea, cause a horse to need extra fluids, even if he seems to be drinking normally. Water loss from diarrhea contributes to fever because thermoregulation is hampered by the water loss.
Drought is another situation to consider when monitoring how much water your horse drinks. In drought conditions a horse’s diet tends to be much drier. Because the grass is dry, he might be eating hay instead of moist grass, and ponds might become low and stagnant. Besides, during droughts it is often deathly hot, causing the horse to lose water through sweating. Where a horse might drink 5-10 gallons of water in the winter, this amount might double to 20 gallons in the hot summer.
A horse owner should know the signs of dehydration. By the time a horse shows early signs of dehydration, he has already lost significant water, about 6% of his body weight. For a well-hydrated horse, gums should be pink and moist. A skin pinch test, in which the skin along the neck and in front of the shoulder is pinched and released, indicates skin elasticity. The skin of a hydrated horse should go back to normal within two seconds. Visual signs, such as sunken eyes or a tucked-up appearance of the abdomen or flanks, indicate a dehydrated state approaching the need for veterinary care. The visual signs usually indicate an 8-10% dehydration level. At a 10% dehydration level, veterinarians administer fluids.
Horse keepers should check and refill water at least once daily. Especially in the summer, it is surprising how quickly a few horses can drain the trough!
More information about dehydration in horses is available from Dr. Eleanor Kellon at Uckele Health & Nutrition at: http://equine.uckele.com/Resources-Articles/cat/drkellon/post/TMG/
Anticipating a hot, dry summer, keeping horses properly hydrated is highly important!
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