Guide
A horse that will not lie down is not sleeping properly.
Horses doze standing up, which is why the problem goes unnoticed. The part of sleep they cannot get on their feet is the part that eventually forces the issue.
Guide
Horses doze standing up, which is why the problem goes unnoticed. The part of sleep they cannot get on their feet is the part that eventually forces the issue.
Ask most people how horses sleep and they will tell you horses sleep standing up. It is half right, and the missing half is the part that causes problems.
A horse can lock the major joints of its limbs through an arrangement of tendons and ligaments known as the stay apparatus, supporting its weight with very little muscular effort. This is a prey animal's adaptation: it allows rest without giving up the ability to move immediately, and it is why a horse can stand for long periods and doze.
What it allows is drowsiness and slow-wave sleep. What it cannot allow is REM.
REM sleep involves near-total loss of muscle tone — atonia. That is not incidental to REM; it is one of the things that defines it. A horse in REM cannot hold itself up, because the mechanism that holds it up depends on muscle tone that REM removes. So REM requires lying down. In practice it usually requires lateral recumbency, flat on the side, or at least a sternal position with the head supported.
Horses are polyphasic sleepers. Rather than one consolidated block, they take sleep in many short periods across the day and night, with the majority of recumbent sleep occurring at night. Total sleep is only a few hours in twenty-four, and the recumbent portion of it is smaller again — commonly cited in the region of thirty to sixty minutes a day, taken in bouts of a few minutes at a time.
That is a small requirement, and it is easy to assume it is being met. It is also small enough that a horse can miss it for days without anybody noticing, because a horse that has not lain down looks exactly like a horse that has.
Recumbency is a decision the animal makes, and it can be prevented by anything that makes getting down or getting up again feel unsafe or painful.
A REM-deprived horse eventually enters REM while standing. Muscle tone goes, and the horse partially or completely collapses — often buckling at the knees, sometimes going all the way down, usually catching itself and coming straight back up. It typically happens while the horse is standing quietly rather than while active.
These episodes are frequently reported as fainting, as a neurological problem, or as narcolepsy. True narcolepsy in horses exists but is rare and usually appears in young animals. Sleep deprivation is very much more common and is, importantly, reversible: the collapses stop when the horse starts lying down again.
The signs worth looking for before it gets that far are physical. Repeated abrasions on the front of the fetlocks and knees, from buckling. Bedding that is never disturbed. Hocks and hips with no shavings on them in the morning. A horse that seems dull or unusually spooky without an obvious cause.
Most of the fixes are unglamorous and cheap. A bigger box or an overnight turnout. Deeper bedding, and enough of it that the horse can get up without scrabbling. A companion, or a stable position with a neighbour it settles beside. A pain workup if the horse is older or has a known joint history. On competition trips, stabling that resembles home more than it resembles a corridor.
The difficulty is knowing whether any of it worked. Recumbency happens at night, in short bouts, and stable cameras produce hours of footage that nobody watches to the end.
That is the measurement problem Ninug Equine is built for: recumbency logged continuously rather than sampled, so "he seems better since we moved him" becomes a number of minutes per night with a date attached. The same record covers travel and competition load, and recovery through a period of box rest — the situations where the debt accumulates fastest and is hardest to see. It is fitted and supported by a professional, and reserved through the shop like everything else.
For other species the questions are different but the principle is the same — continuous, objective monitoring for animals that cannot tell you how they feel. The overview is here, and there are separate pages for dogs and cats and for cattle, sheep, pigs and goats.
Common questions
Yes, and they need it as much as any mammal. A horse sleeps in short bouts spread across the day and night rather than in one long block, totalling roughly three to five hours in a twenty-four hour period. Most of that is dozing and slow-wave sleep taken standing.
In two different postures for two different kinds of sleep. Drowsiness and slow-wave sleep happen standing, held up by the stay apparatus in the legs. REM sleep cannot: it abolishes muscle tone, so a horse has to lie down for it. A horse that only ever stands is not getting REM.
They have to, for part of it. REM sleep requires lying down because muscle tone disappears during it, and a standing horse would fall. Horses lie down for short bouts, usually a few minutes at a time, adding up to something in the region of thirty to sixty minutes a day.
Partly. A horse can lock its limbs through the stay apparatus and get drowsiness and slow-wave sleep standing, but not REM. REM involves loss of muscle tone, so it requires lying down.
Wherever they feel safe enough to stop paying attention, which is the operative condition. A horse will doze standing almost anywhere, but it will only lie down somewhere it feels secure and where the surface gives it enough purchase to get back up — a deep-bedded stable, or a dry patch of field with the rest of the herd nearby and one animal left standing on watch.
Roughly three to five hours a day in total, taken in short bouts rather than one block. Of that, only about thirty to sixty minutes is spent lying down, and only the lying-down portion can contain REM.
Mostly at night, and mostly in the early hours, though a horse will lie down in daylight if it is settled and undisturbed. Bouts are short — a few minutes each — and repeated.
It folds its front legs and drops onto its chest, then rolls onto its side or stays sternal. Getting up is the harder half: the horse rocks forward, thrusts with its hind legs and pushes up with the forelegs, and it needs both room and a surface with grip to do it. A stable too small or a floor too slick is a common reason a horse stops lying down at all.
Mainly, but not only. Horses are not strictly nocturnal or diurnal — sleep is distributed in bouts across the whole twenty-four hours, with the longest and the lying-down portions concentrated at night.
Sometimes. A horse may lie sternal — upright on its chest with legs folded — or fully flat on its side. Flat on the side is the posture most associated with REM, and horses spend less time in it because the weight of the body makes breathing harder over long periods.
Broadly yes. All equids share the stay apparatus that lets them doze standing, and all of them need to lie down to reach REM. Ponies, donkeys and mules follow the same pattern of short lying bouts adding up to well under an hour a day, and the same warning sign applies: an animal that never lies down is not getting REM, whatever else it is doing.
Recumbent sleep is commonly cited in the region of thirty to sixty minutes a day, taken in short bouts of a few minutes at a time.
Pain, a stable too small or a surface with no purchase, feeling insecure in a new yard or without a companion, travel and competition, and box rest are the common causes.
The horse eventually enters REM standing, loses muscle tone and partially collapses, usually catching itself. It is often mistaken for narcolepsy, which is rare. Abrasions on the fetlocks and knees and undisturbed bedding are earlier signs. Collapse needs a vet.
Further reading