You may have heard the age-old saying “you can lead a horse to water, but you can’t make him drink it”, but does it ring true? Essentially it is founded on some truth - horses are reluctant drinkers and may have to be encouraged to lap up their daily water quota. Dehydration is a common threat to horses and if not addressed early on, it can lead to serious health concerns such as kidney dysfunction, laminitis and even death in the most severe cases. Ensuring your horse is fully hydrated is a key step towards a healthy horse however replacing essential electrolytes and salts is equally important when replenishing lost fluids.
Is my horse dehydrated?
Horses lose fluid through a number of different channels including sweating, respiration, excretion and diarrhoea. In hot weather or under harder and longer working conditions this fluid loss can increase significantly. Racing or competing horses are particularly susceptible to dehydration due to the sheer amount of sweat produced during exercise.
The signs of dehydration can range from poor concentration and performance to lethargy and a low mood. Some of the more obvious signs to look out for are darker than usual urine and reduced appetite. You can also check your horses’ gums to see if they are moist; if your horse is adequately hydrated the gums should feel slimy.
The danger with horse dehydration is that when they perspire they not only lose water but also essential electrolytes including sodium, potassium and chloride along with calcium and magnesium. Chloride is lost in the greatest amounts followed by sodium and potassium. Understanding how to hydrate them properly with both water and electrolytes will keep them healthy and less prone to dehydration.
How to hydrate
The average horse needs around 25 litres a day to keep hydrated however this can vary significantly depending on how much work they are doing and what the temperature is. Horses can receive their daily water intake from drinking as well as from food sources. Fresh grass in particular is a great source of hydration as it contains up to 80% water whereas hay only contains about 15-20%.
Ensure that your horse’s water source is easily accessible, clean and frequently topped up. Some horses prefer their water to be tepid as opposed to chilled so test out different temperatures until your horse is happier with it.
If your horse shows little enthusiasm for their water bucket, try and add some flavour for example mint or apple juice. You could also try adding chunks of fruit or whole apples so they can search or bob for their food while consuming water. For a fun alternative treat them to some unique ice lollies, in moderation of course. Freeze their favourite fruit or vegetable in a bucket or cup of water to increase their water intake and give them a tasty treat. A study by the University of Southampton revealed that horses do seem to have flavour preferences with fenugreek, banana, cherry and rosemary coming out top. Other popular flavours were carrot, peppermint and oregano however coriander and nutmeg were not at the top of horses’ wish-list! (1)
If your horse regularly competes and has to travel long distances remember to take a sufficient supply of water for the journey. Similarly on warmer days and during the summer months your horse will have higher water requirements so top up their supplies regularly. When the temperature creeps up it may be a good idea to cool them off with a hose to help limit perspiration and in turn, dehydration.
Replacing essential salts
Whilst rehydrating your horse with water is crucial, it’s also important to restore the vital salts they will inevitably lose through sweating. Electrolytes can help replace the reduced levels of chloride, sodium and potassium. Electrolyte mixes can be dissolved in water or in your horse’s feed. Similarly salt licks or blocks can replace lost sodium and encourage your horse to drink more, just like salty crisps make us reach for the water. If your horse is not particularly enthused by a salt block, try adding loose salt to their feed or water every day. It has been suggested that a horse that is not working will require at least 10 grams of sodium a day which equates to 2 tablespoons (2). When your horse is working or the weather heats up, add more salt. However take care not to add it to their only water supply, simply place another bucket with the added salt.
Most horses are likely to experience some degree of dehydration during their lifetime but if it becomes severe they may need veterinary attention. If you are concerned about your horse’s hydration levels consult your vet.
(1) Goodwin, D et al. (2005). Applied Animal Behaviour Science. University of Southampton: 95, pages (223-232).
(2) Ph. D. Getty, J.M (2010). Feed Your Horse Like a Horse: Optimize Your Horse’s Nutrition for a Lifetime. Indianapolis: Dog Ear Publishing, Pages (24-25).