Why Pregnant Mares Stop Lying Down (And Why It Matters More Than You Think)
Night 1 of Foal Watch: What We’re Really Watching For
Night 1 of official foal watch and both My Audubon (Audi) and Lady Dyanaformer (Dyana) got some deep rest.
And at this stage of pregnancy, that’s not something we take for granted.
Today marks Day 322 of pregnancy for Audi and Day 308 for Dyana—which means we’re officially in that window where everything starts to matter just a little bit more.
Because as mares get closer to foaling, one of the most important—and often overlooked—changes isn’t just physical.
It’s whether they’re still lying down.
Horses Don’t Sleep the Way You Think
Horses are designed to rest while standing.
Thanks to something called the stay apparatus, a system of tendons and ligaments that stabilizes their joints, they can lock their legs in place and relax without falling over. It’s an evolutionary advantage—allowing them to rest while staying ready to move if needed.
But standing rest has limits.
For true deep sleep (REM sleep), a horse has to lie down.
That’s when full neurological and physical recovery happens. Without it, rest is incomplete.
Why Late-Term Mares Stop Lying Down
As pregnancy progresses, especially in the final weeks, many mares begin to lie down less and less.
There are a few reasons for that:
The added weight of the foal makes getting up and down more physically demanding. As their abdomen enlarges, lying flat can also create pressure and discomfort. On top of that, a heavily pregnant mare is more vulnerable in a down position, and instinct can push her to stay standing longer.
So even if she needs to lie down… she may choose not to.
What Happens If They Don’t
This is where things start to matter.
When a mare spends too much time standing without laying down:
Fluid can begin to pool in the lower legs, leading to edema (stocking up).
She misses out on REM sleep, which leads to fatigue over time.
And in more extreme cases, sleep deprivation can cause her to start slipping into REM sleep while standing—resulting in sudden buckling or even collapse.
That last piece is often misunderstood, but it’s not true narcolepsy—it’s the body forcing rest when it hasn’t had the chance to get it properly.
Why We Keep Adding Bedding
This is why, as mares get closer to foaling, we adjust their environment.
We bed stalls deeper and deeper—creating a thicker, softer surface that makes lying down more comfortable and getting back up easier.
At this stage, we’re not just thinking about cleanliness or routine.
We’re thinking about encouraging a behavior that their body may be starting to resist—but still needs.
What We Saw Last Night
Seeing both Audi and Dyana choose to lie down and truly rest on the first night of foal watch is exactly what we want.
It tells us they’re comfortable.
It tells us they feel safe.
And most importantly, it tells us they’re still getting the kind of rest their bodies need in the final stretch.
Sometimes the smallest behaviors are the most important ones to watch.
Follow Along: Foal Watch Is Live
If you want to follow along in real time, you can join us on the Foal Watch page.
You’ll find:
Countdown timers to each mare’s due date
Details about each expected foal
Interactive polls
Live foaling cameras
