How Much Water Does a Horse Drink?

An average adult horse will commonly drink around 25 to 55 litres of water per day.

That is only a guide.

A horse's actual water intake can vary considerably depending on its size, diet, workload, weather and health.

As a rough bodyweight guide, horses may require around 5 to 10 litres of water per 100kg of bodyweight each day.

For a 500kg horse, that works out at roughly:

25 to 50 litres per day

In hot weather or after significant exercise, the same horse may drink considerably more.

Horse water intake at a glance

Using the broad 5 to 10 litres per 100kg bodyweight guide:

Horse weight	Approximate daily water requirement
250kg	12.5 to 25 litres
300kg	15 to 30 litres
400kg	20 to 40 litres
500kg	25 to 50 litres
600kg	30 to 60 litres
700kg	35 to 70 litres

These are not fixed drinking targets.

Some horses will naturally drink more or less, and requirements can rise considerably during hot weather, hard work, lactation or illness.

If you do not know your horse's weight, our Horse Weight Estimator can give you a useful starting estimate.

Horses should have constant access to water

Wherever practical, horses should have continuous access to clean, fresh drinking water.

For stabled horses, the UK welfare code specifically recommends continuous access to fresh water.

Water should not be deliberately restricted because a horse normally drinks a particular amount each day.

A horse that usually drinks 30 litres still needs access to more than 30 litres in case its requirements change.

What affects how much a horse drinks?

Water requirements are affected by several things, including:

bodyweight
temperature and humidity
exercise
sweating
diet
grazing
pregnancy and lactation
illness
travel
individual drinking habits

The amount a horse drinks can therefore change throughout the year without necessarily indicating a problem.

What matters is knowing what is normal for your horse and noticing significant changes.

How much do horses drink in hot weather?

Water intake can rise substantially during hot weather.

The British Horse Society advises that a 500kg horse may drink around 50 to 70 litres per day in hot conditions.

Exercise can increase requirements further because horses lose large amounts of water and electrolytes through sweat.

During warm weather:

keep clean water available at all times
check troughs and automatic drinkers regularly
provide enough water for peak demand, not just normal demand
clean containers regularly
provide more than one water source where appropriate

Do not assume a trough is full simply because it normally lasts several days.

Does exercise increase water intake?

Yes.

Exercise produces heat, and horses use sweating as an important way of cooling themselves.

Sweat contains both water and electrolytes, so harder or longer exercise increases the amount that needs to be replaced.

After exercise, give your horse access to clean drinking water.

The old idea that a hot horse should automatically be prevented from drinking is outdated. Horses need to replace the fluid they have lost.

Where a horse has been sweating heavily, electrolyte replacement may also be appropriate.

Follow the product instructions and make sure plain drinking water remains available.

For horses in hard work, endurance exercise or with particular health requirements, speak to your vet or an appropriately qualified equine nutritionist about electrolyte use.

Does diet affect how much a horse drinks?

Yes.

A horse eating mostly dry forage such as hay will generally need to obtain more of its water by drinking.

Fresh grass contains a large amount of water, so horses grazing good pasture may drink less from a trough even though their total water intake remains adequate.

Haylage also contains considerably more moisture than hay.

This means a sudden reduction in drinking is not always a problem if the horse has also moved onto wetter grazing or forage.

Our Hay vs haylage guide explains the difference in moisture content between the two forages.

You can also read How much hay does a horse need? for more on forage intake.

How can I tell how much my horse is drinking?

Buckets make monitoring relatively easy.

Start with a known amount and check how much remains later.

For example, if you provide two 25 litre buckets and 20 litres remain the following morning, approximately 30 litres has disappeared.

Remember that some may have been:

spilled
knocked over
used to soak forage
contaminated and discarded

So it is still an estimate.

Automatic drinkers are convenient but can make it harder to see how much an individual horse has consumed unless they are fitted with a suitable meter.

What is often more useful is noticing a change from the horse's normal pattern.

Buckets or automatic drinkers?

Both can work well.

Water buckets

Buckets make it easy to monitor approximately how much your horse drinks.

They are also simple to inspect and clean.

The disadvantages are that they can:

be knocked over
run empty
freeze
become warm or dirty
require frequent filling

If using buckets, make sure enough water is available to comfortably cover the horse's requirements.

One small bucket may not be enough for a horse overnight.

Automatic drinkers

Automatic drinkers can provide a continuous supply without carrying buckets around the yard.

However, they need regular checking.

A bowl that looks perfectly normal is no use if:

the pipe has frozen
the valve has failed
the flow rate is too low
the water supply has been isolated
the horse does not understand how to use it

When introducing a horse to an automatic drinker, make sure it is actually using it.

Providing a bucket as well initially is sensible.

Water in the field

Field troughs should contain clean, fresh water and should be checked regularly.

Keep an eye out for:

algae
contamination
damaged pipes
failed ball valves
leaks
frozen supplies
empty troughs
horses preventing others from drinking

Where horses are kept in groups, more than one water source can help prevent a dominant horse from restricting another horse's access.

Natural streams and ponds should not automatically be assumed to provide a safe or reliable water supply.

They can become contaminated, dry up or become difficult to access.

Do horses drink less in winter?

They can.

Cold water, frozen troughs and reduced activity can all affect drinking behaviour.

At the same time, horses may be eating more dry hay during winter.

That combination can increase the risk of digestive problems if water intake falls too far.

The British Horse Society warns that inadequate water intake in winter can increase the risk of impaction colic.

During freezing weather:

check buckets and troughs frequently
break and remove ice
make sure automatic drinkers are working
keep an emergency water supply if pipes may freeze
consider adding some warm water to buckets

Some horses are more willing to drink slightly warmer water during cold weather.

What are the signs of dehydration?

Early dehydration can be easy to miss.

Possible signs include:

drinking differently from normal
reduced or darker urine
fewer droppings
drier droppings
lethargy

More significant dehydration can cause:

dry mouth
thick saliva
dull or sunken eyes
increased heart rate
abnormal gum colour
slower capillary refill time

No single home test can reliably tell you exactly how dehydrated a horse is.

Look at the whole horse and its behaviour.

If you suspect significant dehydration or your horse appears unwell, contact your vet.

What if my horse suddenly drinks much more than normal?

A horse drinking more during hot weather or after exercise can be completely normal.

A persistent or unexplained increase in thirst is different.

Likewise, a horse that suddenly drinks considerably less than normal may need attention.

Changes in drinking behaviour can occur with health problems, so contact your vet if:

drinking changes significantly without an obvious reason
the change persists
your horse is producing unusually large or small amounts of urine
appetite changes
your horse seems lethargic or unwell
you are otherwise concerned

Knowing your horse's normal drinking habits makes unusual changes much easier to spot.

What about travelling?

Horses may drink less during transport, particularly when they are stressed or offered unfamiliar water.

For longer journeys, plan opportunities to offer water.

Current BHS dehydration guidance recommends offering water during rest breaks on long journeys, with breaks planned around every three to four hours.

If you carry water in your horsebox, remember that it is surprisingly heavy:

1 litre of water weighs approximately 1kg.

So:

20 litres = about 20kg
50 litres = about 50kg
100 litres = about 100kg

That weight counts towards your vehicle's available payload.

Use our Horsebox Payload Calculator if you need to check how water, horses, passengers and equipment affect your remaining carrying capacity.

Can I encourage a horse to drink more?

If your horse is reluctant to drink, first make sure the water itself is clean, fresh and easily accessible.

You can also:

offer more than one bucket
try slightly warmer water in cold weather
keep water containers clean
wet or soak appropriate feeds
offer water regularly while travelling
provide a larger bucket if your horse dislikes small drinkers

Some horses will drink flavoured water.

If you use a horse-safe flavouring to encourage drinking, keep plain water available as well so the horse always has a choice.

If your horse is refusing water or appears dehydrated, contact your vet rather than relying on tricks to encourage drinking.

Water from soaked feed still counts, but do not rely on it

Wet feeds, soaked hay, haylage and fresh grass all contribute water to the horse's overall diet.

They can be useful ways of increasing fluid intake.

But they do not remove the need to provide fresh drinking water.

A horse should still be able to drink freely.

Check water every day

Water provision should be part of your normal daily checks.

Check that:

water is available
containers are clean
automatic systems work
troughs have not frozen
buckets have not been knocked over
the horse appears to be drinking normally

A water supply that worked yesterday is not guaranteed to be working today.

Useful StableMetric tools and guides

Horse Weight Estimator - estimate your horse's bodyweight
How much hay does a horse need? - work out a starting forage requirement
Hay vs haylage - understand how forage moisture differs
Horsebox Payload Calculator - check the effect of carrying water and other loads when travelling

The simple answer