How much water do horses actually drink?
- An average 550-600Kg horse is likely to drink between 25 and 35 litres of water per day. However, intake between individual horses can vary widely – some will drink as little as 2 litres others as much as 50 litres.
- Fresh pasture grass can contain 60 to 80% water and has the potential to provide most of the water a horse needs, especially in wet conditions. As such, a horse may not feel the need to drink very much but the aim should still be to have a constant supply available.
- Animals grazing on bare pasture, or during a period of drought, or in very cold weather, will always drink more water.
- It is important to know that SALT IS NEEDED in the diet of all horses and ponies, in order to trigger a proper thirst response.
Why does a horse need water?
- Water is an essential nutrient for all animals – it supports EVERY system in the horses’ body.
- The digestive system and the horses’ ability to regulate body temperature (thermoregulation) are seriously affected by a shortage of water in the body. When water levels in the body fall, there is a risk of dehydration.
- Lost water must be replaced. Research has shown that even a 3 -4% loss of body water will cause mild dehydration.
600Kg horse facts:
50 litres of blood run through its veins
40 litres of saliva are produced every day, to aid digestion.
When will a horse need more water than usual?
- Horses, even those in light work, will sweat to cool themselves down. When horses’ sweat, they lose both water and salts (electrolytes).
- Sweat evaporates rapidly – so a warm horse (not visibly wet with sweat), will still be losing both salts and water.
- Electrolytes are important substances that control blood volume, muscle and nerve function.
- Horse sweat contains up to seven times more salts per litre than human sweat – that’s why horses have a much lower thirst stimulus than humans.
- If a horse is in training, replacing water alone, will not replenish lost salts. Electrolyte replacements can therefore be used – available from a tack or feed merchant; they can be added to feed or water or syringed directly into the horse’s mouth. Ask your Vet for advice.
If electrolytes are added to water – plain water must also be available to the horse.
What other factors affect water intake?
- Mares with a foal at foot – lactating mares require 50-80% more water per day for milk production compared to other ‘normal’ grazing horses.
- Horses eating hay and dry feed only will require extra water, as they will be receiving very little moisture from food.
- A horse that is scouring (diarrhoea) will require more water and electrolytes.
- In hot weather, the horse can get heated and although not visibly sweating will be losing moisture and salts through the skin.
- A horse in unfamiliar surroundings – or offered water from unfamiliar containers or water sources, may refuse to drink. Horses have been proven to prefer water with neutral pH levels and there is some evidence that lukewarm temperature is preferred – especially in colder weather.
Does it matter if the water is dirty?
- All animals should have access to fresh, clean water 24/7.
- Standing water becomes stale, picks up taints and ammonia and algae will grow – all of which can deter a horse from drinking.
- If a horse is forced to drink water that is not clean, it can take in bacteria, which can compromise well-being.
- Unlike us, horses are unable to vomit; therefore, anything swallowed, even if it makes them feel sick or unwell must pass through the digestive system.
- It is recommended to scrub and refill water containers and automatic drinkers daily. Field troughs should be checked daily and cleaned out as necessary – at least every couple of weeks.
- Horses will not drink water contaminated with faecal matter (poo), so it is VERY important to check the supply at least once a day.
How long is too long without water?
- There are times when it is impossible for your horse to have water 24/7. For example, when travelling or perhaps a tethered horse that can knock the bucket over.
- Horses in these situations should be offered water every 2-3 hours.
- Horses can however adapt to periodic access throughout the day if the amount of water offered at those times is not limited.
- Soaked hay or haylage and lush grass, have a higher moisture content than hay. Water can also be added to hard feeds to increase intake.
- The basic rule however, which should be followed if at all possible is to have fresh water available for horses at all times.
What happens if a horse does not get enough water?
- Like humans, after three to four days without water, the organs will begin to shut down.
- A horse deprived of all water and any moisture from food, may live 3-6 days
- If a horse does not drink enough water there is a real risk of colic (abdominal pain) because of digestive impaction. This is a serious condition and requires veterinary attention.
- When dehydrated, the horse will experience various symptoms: elevated heart rate, gums dry and darker in colour, and skin less elastic.
- Once the horse is 8-10% dehydrated it will appear sick and display sunken eyes, a tucked up abdomen, be suffering headache, nausea and exhaustion and require urgent veterinary attention.
Should horses have access to a salt lick?
- Every horse benefits from taking in salt daily. Some will need more than others.
- Salt plays an important role in maintaining good health.
- Low salt levels in the body means the horse will not feel thirsty. It will fail to drink sufficiently and potentially become dehydrated as a result.
- Horses will actively seek out and consume salt/minerals from the earth and even from treated wood. Sometimes, soil and grazing conditions will not allow for this, so owners should always provide the horse with unlimited access to a salt lick or block.
- Salt blocks can be purchased from a tack shop or feed merchant.
- Sprinkling a teaspoon of salt on feed once a day will help maintain sodium and chloride levels for horses resting or in light work.
- Horses in hard work and sweating on a regular basis are likely to need further supplementation. Ask your vet for advice.
Horse sweat contains up to seven times more salt per litre than human sweat. Lowered salt levels in the blood can cause the horse to not feel thirsty. It is therefore quite possible, that a horse which has worked hard and sweated heavily, will refuse a drink when offered.
This could explain the origin of the phrase ‘You can lead a horse to water but you cannot make it drink.’
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