When did you last have a drink of water? It’s so easy, isn’t it, when you have easy access to a tap or bottle, but when did you last spare a thought for your horse’s access to this elixir of life?

A horse’s body weight is made up of around 62-68% of water, and they can become perilously dehydrated if they lose between 8-10% of their natural body water. This is why it is imperative that they have constant access to a fresh, clean supply at all times, both in the stable and pasture, 24 hours a day.

An average horse – 15hh/500kg – will need to drink around 30-50 litres per day, and this amount will be higher in hot weather, or if working hard. Also a mare with foal will need more due to lactating.

If your horse is grazing on lush grass, he will drink less because the grass will contain water, whereas more mature grass and hay is drier, so more water will be needed.

All water offered to your horse must be clean. If he is forced to drink water that is contaminated with algae, manure/urine or dirt, he could become ill, and as a horse cannot vomit, this polluted liquid has to pass through his system.

However, horses do have a good sense of smell and, should the water be polluted, stagnant or if the supply changes suddenly, they could refuse to drink completely to the point of dehydration.

So why does your horse need so much water?

The naturally high fibre diet of your horse means that a high level of water is needed to ensure it moves through the digestive system correctly. If a horse has restricted access to water, or has poor quality water, and so therefore does not drink a sufficient amount, he could be at risk of impaction colic and will probably need veterinary attention.