First broadcast on on May 15th 2000.

This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Access to an adequate water supply is extremely important. If losses of water from the body exceed intake the horse or pony will quickly become dehydrated which affects performance, and can lead to colic and even death.

About 70% of the body is made up of water, and water is lost from the body every day through :

  • Urine - high protein rations increase water losses in urine
  • Faeces - diarrhoea greatly increases water losses by this route, and can be life-threatening, particularly in young foals
  • Sweat - sweating is a major way that horses maintain body temperature during exercise
  • In air expelled from the lungs - these losses increase during exercise when breathing rate increases
  • From the skin - evaporation rate increases in high environmental temperatures
  • Milk in lactating mares

During lactation and strenuous exercise a horses water requirements can increase by anything from 20% to 300% . Even during trotting a horse may lose over 9kg water and during endurance rides some horses can lose up to 10% of their body weight as water loss. In man loss of only 2% body weight can adversely affect performance, and water loss is an  important component in equine exhaustion syndrome. So, maintenance of adequate water intake prior to and during endurance exercise is important.

Some foodstuffs, such as hay (high in fibre) and pelleted foods will bind with water and keep it in the gastrointestinal tract. Water intake increases, and can even double,  in horses fed hay. It has been estimated that horses drink 2-3 litres of water/kg dry matter of food.

Horses and ponies should have free access to a clean, fresh water supply that is not contaminated. Water troughs should be kept clean, and water should not be allowed to stagnate. The water supply for horses and ponies kept in fields in agricultural areas should not be exposed to pesticide sprays or other agrochemicals that could be potential toxins. Old lead-lined water troughs should not be used because of the risk of lead poisoning. Rivers or lakes made available to horses or ponies as a water supply should not be subject to pollution, or be used for the legal disposal of industrial waste materials or sewage.



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