Why Salty Water Might Help Keep Your Endurance Horse Hydrated

Hydration in Endurance Horses

Keeping healthy levels of hydration in endurance horses is a massive challenge and many people wish they could increase water intake for their horses. And a big part of the challenge is that horses have a tricky (I call it just plain annoying) thirst response trigger.

For horses to ‘feel thirsty’ they need a certain level of sodium in their blood. BUT when they drink fresh water, it dilutes their blood sodium and that can switch off their thirst response, even if they are still dehydrated!

Which means you can have a thirsty (i.e. dehydrated) horse that isn’t actually ‘thirsty’! See … told you it is annoying.

But since we can’t magically rewire this system, we need to work with it.

And there is a really simple, very cheap workaround to get your horses drinking more and rehydrating faster.

And that is…

To offer their first drink of water when coming into a vet check as salty water!

To be specific… 0.9% salty water!

To make 0.9% salty water, mix 90 grams of salt (sodium chloride, also known as table salt) into 10 litres of water.

Using 0.9% salty water has been shown by research to increase water intake in horses

Research (Butudom et al 2002) showed that horses who were offered 0.9% salt water as their first water offering after being dehydrated drank 18.5 litres of water in total (of salty and then fresh water) in the first hour after finishing exercise.

Compared to…

Horses that were offered just plain water as the first and all subsequent water offerings after finishing exercise, who only drank 11.4 litres of water.

The reason the salt water ‘works’ is because when given salty water it maintains blood sodium levels and therefore maintains a thirst response which means horses will keep drinking.

How to put this into practice (& get your horse to drink more water)

Here is how to do this properly:

1. Make up your salt water solution by adding 90 grams of salt (sodium chloride) per 10 litres of water.
2. Offer this salty water as the first water your horse has access to when coming into a vet check.
3. Let them drink as much of the salty water as they like during their first drink. The horses in the study drank close to 12 litres of this water on their first post-exercise drink.
4. THEN, give them access to fresh water (no salt) for the rest of the time they are ‘in camp’. What should happen is they will still feel thirsty and drink more of the fresh water. The horses in the study drank close to an additional 7 litres of fresh water.

It is REALLY IMPORTANT to get your horses used to drinking the salty water at home during training! Once they get used to it, you should find they will very happily drink it.

Happy training! Hope this helps keep your horse hydrated and you less worried!

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