In this article we look into why horses sleep and the importance deep-sleep plays to their overall health. We discuss the value to owners in being aware of their horses sleeping patterns to help detect early signs of lameness or injury, and we talk about how horses sleep standing up, why they lie down and what to do if your horse won’t stand up.    

Why is my horse lying down in the field!?

Quite often, you will see horses lying down in their field and even see them having a sleep standing up against their field-mate.

Remember, like us, horses like to lie down when they go into deep sleep, but they naturally lie down when they are resting after exercise or when the are sick or injured.

Occasionally - which some of us can relate to - we arrive at the yard and see our beloved horse lying down flat in the middle of the field, in the middle of the day, and panic!

In the vast majority of cases they are simply sleeping, yet the consequences of dealing with something more serious, such as an injury or sickness, naturally heightens our anxiety levels.

Seeing your horse laying down can mean many things. Have they torn a ligament bucking around? Have they caught a virus, or worse? It is important not to panic until you really know why they are lying down.

Understanding your horse and at what times of the day they like to sleep, where they lie down and how they fall asleep, is an important lesson when understanding each individual horses sleep patterns. Knowing these sleeping routines can really help and although it can be a slow process to fully learn,  it can be an extremely beneficial tool moving forward.

Your horse is probably sleeping

The most common reason why your horse may be lying down is that they are sleeping - this is completely normal.

Horses sleep differently to humans – rather than sleeping for one longer period like we do, horses have many shorter and more discrete periods of sleep during a 24 hour period.

Horses are known as ‘polyphasic sleepers’ meaning they have multiple short periods of sleep, sometimes in the day time but mostly at night.

Some of this sleeping occurs while the horse is lying down on their side, while some sleep will be achieved when the horse is standing upright.

Younger horses and foals tend to spend more time lying down and sleeping than older horses do, but other factors such as feeding and turnout management can also influence how much time a horse spends sleeping while lying down.

Do horses really sleep standing up?

Many horses will chose to have quick sleep in the day time and are often seen doing this standing up. Horses are able to sleep standing up because their legs can ‘lock' into place in both their fetlock and hock joints, meaning that they can rest and sleep without falling over. This is often referred to as their ‘stay apparatus’ and is quite unique to a horses anatomy as their ligaments and tendons lock into place without exerting the muscle and using up the horses energy reserves.

It is thought that they evolved this ability to sleep standing up as they needed the ability to escape predators when living within their herd community in the wild. Horses seen sleeping in the wild are also seen facing in the same direction; this is thought to be another safety mechanism so if they do require a quick exit that they don’t bang into each other!

Although horses and ponies are able to sleep standing up, it is important to understand that this is only a form of ‘light sleep’ and that they do require a period of lying down to enter into full deep-sleep.

Many horses will not lie down and achieve ‘deep-sleep’ if they are not fully comfortable, warm and feel safe and secure. Because of this it is vital that all horses are given the adequate conditions and a safe environment to sleep. Ensure your horse is provided adequate bedding and a warm and dry place to lie down.

Horses who do not have adequate periods of time in ‘deep-sleep’ will likely suffer from sleep deprivation, which is a vital aspect of the horses overall health.

Although equine sleep disorders are poorly understood and very few peer-review studies have been carried out on horse sleep deprivation - many owners and vets are left to manage their horses sleep patterns through personal understanding of their horse rather than evidence-based treatments.

How do horses sleep?

As is the case with humans and most mammals, horses go through a series of cycles during sleep time. Each of these cycles can be characterised very differently and will vary from horse to horse so once again it is important to understand the individual horses needs and routines.

In the majority of cases horses will begin to fall asleep standing up, not always will a horse lie down to start their sleep.

As they begin to drop-off their heads will begin to hang and their bottom lip will often become relaxed and loose. As the horse begins to drift further into sleep their head will likely hang down further and as long as the horse is feeling safe and secure it will begin to lie down. (Known as Lateral recumbency). In some cases, and particularly in the day time, they may not lay down but instead choose to sleep standing up.

Not until the horse is lying down will they reach the rapid eye movement stage of sleep (REM) which is occasionally referred to as ‘paradoxical sleep’. In this stage of sleep the horse will have their eye lids completely closed and their muscles will be completely relaxed.

Rapid eye movement (REM) sleep relaxes the muscles further while increasing the horses brain activity, meaning that the horse needs to lie down while in this deeper sleep stage to achieve the recovery process their body needs.

During REM sleep, horses are likely to be lying on their side, in a sternal position (lying on their chest or side) or leaning against something to help support their weight. However, it is important to note that horses do not spend too long in REM sleep in a day so if your horse is spending significantly longer than this lying on the ground, then there may be another cause of concern.

While you may only be concerned about your horse lying down, it is also important to check that they can for this short period reach that REM sleep level. This is because, without this deep sleep, they can begin to experience sleep deprivation. Sleep deprivation in horses can lead to a number of further issues, including drowsiness and instability on their legs. Often, they will collapse to their knees and then wake back up with a jolt – this process can cause trauma to the fetlocks, hocks and other joints, leading to pain and further health complications.

How long do horses sleep for?

In the vast majority of horses, they will deep sleep between 1 to 4 hours each day. In most scenarios they will sleep from 8pm to 5am and experience REM sleep between 12am and 4am.

It is widely viewed that horses need a minimum of around 3 to 5 hours sleep per 24-hour period.

If your horse has not slept properly (whilst lying down) for 2 to 3 days then it is advised to speak medical advice as sleep deprivation will set in after this period of time.

Types of sleep deprivation in horses

It is widely accepted that there are four main recognised types of equine sleep deprivation, each requiring careful management. Let’s take a quick look at each one.

1) Pain Associated Sleep Deprivation

Pain-associated sleep deprivation is likely to be the most common form of sleep deprivation found in horses. This is caused by painful conditions such as joint conditions or diseases such as navicular or equine arthritis. Issues such as Kissing Spine and other musculoskeletal disorders can create heightened pain levels and as a consequence of this pain and discomfort the horse is unable, or unwilling, to lay down comfortably and thus achieve levels of deep sleep which they require. This form of sleep deprivation is also seen in late pregnancy mares. Providing the horse with adequate treatment and therapies is an important step in helping pain associated sleep deprivation. Many look at supplement and dietary requirements and health-related tack to provide ongoing support to their horses joints.

2) Environmental Insecurity Sleep Deprivation

As we touched on above, providing your horse with a safe and security is vital in allowing them to sleep properly. Environmental insecurity can be caused by one or several factors including their stable location, a loss of field-mates, a lack of warmth or feeling unsafe in their surroundings. This will prevent the horse from achieving the level of sleep they require and as such deprivation kicks in. Ensuring warm and clean bedding is a must.

3) Monotony-Induced Sleep Deprivation

This form of sleep deprivation is most often diagnosed in animals who are tied up for long periods of time and not provided with time to move about. This can be seen in police horses, show horses and elderly retired working horses. If your horse is experiencing this form of sleep deprivation then exercise and light activities will be required to ensure your horse is moving and flexing their joints and muscles.

4) Dominance Displacement Sleep Deprivation

As herd animals some horses are naturally more dominant than others. If a horse is excessively dominant with its herd this can lead to dominance displacement sleep deprivation as the horse is unable to fully relax and achieve levels of sleep they require. Often more common in geldings, this form of sleep deprivation leads to the dominant horse being anxious and unhappy and is often resolved by introducing of a mother dominant mare to the herd.

Once you are confident that your horse is achieving their required levels of sleep, and they continue to lay down in the field for longer than they should, this could indicate a health problem which requires investigation.

Your horse may be suffering physically, sick or injured

If you notice that your horse is lying down for a long amount of time, even when they are not sleeping, then they may be in pain due to a physical condition.

One thing to look out for is if your horse is rolling around or pawing the ground when it is lying down. This is a sign that the horse may have colic, and you should consult your vet immediately as this condition can often be fatal. Colic is a condition that occurs in the horse’s intestines that can be caused by it eating too much grain. There are also other causes such as a parasitic infection, lack of water or tainted food. It is important to try and get the horse walking if this is the case as this can relieve pressure on the intestines.

If a horse is lying down for excessive periods of time, it can also be a sign of musculoskeletal problems, often indicated when the horse is struggling to get up off the ground or stand. This is generally not when only one single limb is affected but is usually when a condition impacts more than one limb, such as arthritis, laminitis or other specific joint conditions or injuries.

Look for lameness and if you recognise any signs of lameness in your horse lying down then call your vet immediately.

Remember that you are not going to be in a position to monitor your horse 24x7 and in some cases horses may fall or slip when playing in their paddock and can sometimes create an injury. Recognising a horses injury is common place in managing your horse health, so take the time to carefully inspect the horses legs and joints as often as possible by carefully running your hand down their legs and spine and check for any indication of inflammation or heat. Look for commonly found hoof problems as these too can be painful and lead to your horse laying down.

Additionally, some neurological conditions that impact the brain can lead to a horse lying down as it can cause issues such as a lack of coordination or general weakness, meaning that a horse struggles to walk, stand or hold its weight. If this appears to be the case, and you notice your horse struggling to get up or not getting up at all, contact a vet for advice and a medical diagnosis.

Your horse may simply be tired

While you may be worried about there being a physical cause to your horse lying down, it may simply be down to them feeling tired and needing to rest. If they have been running around their paddock or been taken on a long ride, they may just need some time to recover.

A key aspect of a sports horses daily routine, and ensuring they remain in tip-top condition, is their continuous and ongoing recovery program. Just with us, when they have pushed their muscular system within their activity their muscles need to relax - and the best way to help relax their muscles is to lie down.

Directly after exercise, horses may wish to cool down by gently walking or having a bath in some cool water and then taking time to relax - if there is enough space for them to do so. It is important that you provide your horse with a dry area to lie down after exercising. If it's the summer then an area of shade which is cool for them to lie down is important, and likewise in the winter a warm and dry place for them lay down is vital. 

Many owners understand the importance of their horses recovery after exercise and now adopt techniques such as using advanced magnetic bands and regular visits to a physiotherapist to aid this ongoing recovery process.

What do you do if your horse is stuck when lying down?

If your horse is lying on the ground and cannot get up, it is important to call a vet straight away to help work out what is wrong. Ideally, unless you have a lot of experience, it is best to leave them lying down at this stage as they are incredibly strong and large animals. If you are attempting to help the horse up, ensure that another person is there to help you.

Make sure that the horse is aware of your presence instead of sneaking up on it as this can spook or startle it.

If you have contacted your vet, they may ask you to try and roll the horse over to its other side in order to take the pressure off the side it is lying on. This may also lead to your horse standing by itself.

Often, you can try and move parts of the horse’s body to help it get up but try to stay away from the back as this is where you are most likely to be injured if your horse does bolt, kicks its legs or suddenly get up.

To conclude…

If you notice that your horse is lying down more often than usual or for longer periods of time, it is important to monitor this situation to observe whether something may be impacting its health. Knowledge, before any potential issue occurs, is key. Learn about your horses sleeping routines.

One of the best ways to then manage a concern is to record (and compare) that horses movement as closely as possible for a 24-hour period to establish and identify any issues or patterns that may be visible.

The reality is that in most cases no one knows your horse better than you and whoever cares for them. You are likely to be the best placed people to recognise whether there is a cause for concern or not.

If you have any doubt about your horse’s health, it is important to get them checked out, even if it is just to be safe. Tips on what you can do in the summer, autumn or winter months can be of benefit as the overall health of your horse is more important than…..well.....everything! :)