Why Do Horses Sleep Standing?

by PetsBlogs on January 10, 2014 (original poste date)

in Horses

All it takes is sleeping on one international flight to convince anyone that lying down is the only way to get a good night’s sleep. However, not all mammals sleep lying down. Horses, despite the tiring look of their heavy, long bodies, actually do most of their sleeping standing up — and it’s more than a quirk of the species – there’s a scientific reason why.

It’s part of their survival

The root of horses sleeping while standing comes from their days in the wild and their “fight or flight” response. Rather than fight like some animals do when attacked, horses, being herbivores, are more inclined to flight, or run, from their predators. Since they have a difficult time standing up once they lay down, standing gives horses a higher chance of survival.

Horses can relax while standing

Remarkably, their bodies are also biologically designed to sleep while standing. Horses have a “stay apparatus”, which is a system of tendons and ligaments that keep the horse in the standing position while their muscles are able to relax. In their front legs the stay apparatus is always intact, but in their hind legs a horse has to rotate their hip and hook one bone over a knob of another bone to put the stay apparatus into effect. The stay apparatus not only allows the horse to stand for long periods of time, but to stand comfortably — a radical difference from our muscles that contract and ache after standing thirty minutes too long.

They still need to lie down sometimes

However, horses aren’t devoid of the need to lie down and sleep, as horses — just like us — need rapid eye movement (REM) sleep, and without it, it will eventually lead to their death. Yet the average eight hours of REM sleep we need a night is hardly the same for a horse, who on average needs 15-20 minutes a day, or an hour or two every few days, depending on their age and if they’re domesticated.

Horses will always wait to get their REM sleep until they feel safe, which is why domesticated horses often get more REM sleep than wild ones. Though you still won’t see your average family horse lying around for too long, as horses who spend too much time lying down can constrict blood flow to the large muscles in their legs, making standing up again very difficult.

In the wild, where horses get the least amount of REM sleep, it’s common for other horses to sleep while standing, allowing one horse to sleep lying at a time and ensuring they’re ready to run if a predator gets near.

Sleeping while standing has its benefits

The next time you pass a horse standing up he might be sleeping. And don’t feel too bad that they have to sleep standing, in fact, maybe you should even feel jealous, as who wouldn’t want to take a quick snooze while waiting in a long line at the DMV or grocery store. 

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Judi, Senior Editor at PetsBlogs

Devoted pet owner and now, devoted pet editor, Judi spent her time working in traditional offices, keeping the books and the day-to-day operations organized. Taking her dog to work every day for over a decade never seemed odd. Neither did having an office cat. She knows what it's like to train a new puppy and she's experienced the heartache of losing beloved companions.