1. Horses are polyphasic sleepers, requiring a total of between 2.5 and 5 hours of sleep in each 24-hour period.
2. Horses usually get their required sleep through a series of short naps in varied positions.
3. Horses have a unique mechanism called “stay apparatus” that allows them to lock their joints and remain standing while they rest, which is known as “resting but alert” state.
4. There are five stages of sleep – alert wakefulness, diffuse drowsiness, intermediate period, slow-wave sleep and paradoxical (REM) sleep.
5. Horses are classified as “obligate non-REM sleepers”, which means they must lie down to achieve a deep sleep state.
6. When a horse does lie down for deep sleep, it typically lasts for around 30 minutes to an hour. During this time, horses may experience rapid eye movement (REM) sleep, which is associated with dreaming.
7. Horses often sleep more during the night, when it is dark and there are fewer potential threats in their environment.
8. Sleep phases are typically distributed between the hours of 8pm and 5am, with the most slow-wave and REM sleep phases occurring between the hours of midnight and 4am.
9. In the wild, horses will often take turns standing guard while others in the herd sleep. This helps to protect the herd from predators and ensures that at least some horses are always alert and able to flee if necessary.
10. Some horses may prefer to sleep alone, while others may prefer to sleep in groups or near other horses for safety and companionship.
11. The introduction of new horses or the removal of horses from a stable herd may disrupt the herd dynamics and have a negative effect on the amount of sleep the individuals are getting.
12. Foals tend to sleep for longer periods than adult horses, as their growing bodies require more rest.
13. Horses can sleep in three different positions. Each position allows your horse to reach a different level of sleep. 1) Standing – the lightest level of sleep and the safest position for a prey animal. Your horse can easily wake and run away from danger. 2) Semi-recumbent (on the ground but more upright, with the legs tucked underneath) – your horse can enter a deeper sleep than if they were standing but is still able to stand up quickly and run away. 3) Fully recumbent (flat out on their side) – this is the position where your horse can reach deep, restful REM sleep. Deep sleep is the most difficult to wake up from.
14. In a 24-hour period, horses require a minimum of 30 minutes for recumbency to fulfill their REM sleep needs.
15. REM sleep creates a loss of muscle tone. To avoid sleep deprivation your horse must be able to lay down and complete a full sleep cycle.
16. Due to their size horse’s can only lay fully out for 45 minutes a time or risk crushing internal organs.
17. Deep rest and sleep is when the horse builds and repairs muscles and other tissues.
18. Deep rest and sleep is when the horse grows and strengthens connections in the brain.
19. Horses with physical injuries, musculoskeletal discomfort, illnesses like respiratory or digestive issues or who are overweight may have difficulty finding a comfortable sleeping position.
20. Horses that are anxious or stressed may have trouble falling asleep or staying asleep.
21. Excessive noise or light, uncomfortable sleeping surface, poor weather or lack of space to lay down in a stall or at a safe distance from a dominant pasture mate can all disrupt a horse’s sleep.
22. Changes of environment are stressful for horses – when horses move to a new barn they will often not sleep at all for the first few days and will experience reduced sleep for up to a month while they try to settle in.
23. Potential consequences of sleep deprivation in horses include increased stress, anxiety or irritability, reduced performance, weakened immune system, digestive problems such as colic or gastric ulcers and reduced strength and stamina.
24. REM deficiency may cause your horse’s body to enter REM sleep while standing. If they enter REM sleep while standing the accompanying loss of muscle tone will cause them to collapse and fall before suddenly waking up. Falls like this can injure knees, head, fetlocks, and hocks, and cause muscle strains and bruising from impact and sudden movements.
Deep rest and sleep play a crucial role in maintaining your horse’s physical and mental health. It’s paramount that their routine and environment supports healthy sleep habits.
If your horse is stuck in a state of anxiety, massage can help your horse relax back into a parasympathetic state, which is where the body takes care of tasks like rest, digestion, repair and regeneration.