My mother had a dog when she was younger that was chasing something and ran into a tree, killing itself instantly.
And no, horses are not stupid. Perhaps by the way humans determine intelligence, but you’re talking about a prey animal, who survived by being faster than the predator chasing them or being faster than the rest of the herd.
I saw a horse die by running itself into a wall at a rodeo.
A guy I went to school with was passing football and got hit in the forehead by the ball, putting him in a coma where he died a week or two later. This was when he was 20-22 years old, not when he was a kid. The moral of the story is not to run your head into things or things into your head. You might survive something that seems very deadly but something that doesn’t seem dangerous can be fatal as well.
Running fast is not the same as intelligence. At least in my book.
I cannot think of horses as intelligent animals. I cannot think of horses as doing anything which requires intelligence. Dogs yes. Crows, yes. Octopus, yes. Horses? Nah.
An animal that is so easily spooked and then runs head-on into a wall and kills itself is pretty stupid in my book. YMMV.
I was at that game. Some background:
One of Texas Tech’s football traditions is the Masked Rider, an individual dressed up a bit like Zorro who rides a horse on the sidelines. Formerly, the Rider would charge full-speed around the field after a Tech touchdown. The Masked Riders no longer do this, because of what happened at the aforementioned game.
That year, a new horse was chosen to be the mount for the Masked Rider. This young horse, Double T, was evidently very high-strung; I remember before the game that he behaved pretty nervously as the new Rider rode him around the stadium. It was the first game of the season, and therefore the first time the horse had been in the stadium during a game, with a huge crowd present.
When Tech scored its first touchdown, the band played, the cannon roared (another tradition), and the Masked Rider set off around the field. The horse just couldn’t handle all the noise and craziness, apparently, and he set off at a flat-out panicked run. For most folks, the horse and rider disappeared from view as Double T headed into the tunnel from which the players entered the field. There, the Rider fell from the horse, which skidded on the concrete, smashed headlong into the concrete wall of the tunnel, and died shortly thereafter. The Rider, as I recall, suffered a broken arm. The horse was soon replaced by another horse with the same name.
So, yep, a horse can die from running into a wall completely under its own power.
Way back during my misspent youth I was at a party where the home owners cat had been heavily dosed with LSD (before I arrived).
It dove headlong into a wall and snapped it’s own neck. 
To answer the OP, yes, of course this is possible. It’s not like the question, “Is it possible to hold your breath and suffocate to death?” - which is impossible, by the way.
It apparently happened last week near Kansas City, MO
Naw, all you need is regular glass and a lawyer.
Well with some tools to assist you, say plugs for your nose and some duct tape for your mouth, yes, you could technically hold your breath and then die.
Well that was morbid.
If you’re a quadruped you’ve got head and spine lined up to take the full force of collision busting up your neck. Bipeds would have to lower their heads for neckbreaking to happen. Unless you’re dying from having your brain smashed around.
Horses have a nearly 360 degree view, thanks to their side-placed eyes, typical of a prey animal. Their blind spots are directly behind them (which is why one should never approach a horse from behind), and directly in front of them. Drop a carrot on the ground and watch them “find” it…their muzzle does all the work after a certain point as they cannot see exactly where it is.
A panicked horse will succumb to its instinct to flee and run, and run blindly. A friend of mine lost two of her horses in one of the weirdest fluke accidents I have ever heard of–her two young geldings panicked in their pasture and ran head on into each other. It happened not 50 feet from her; she heard their necks snap. One died instantly, the other, shortly after.
I understand why someone would consider horses dumb animals–I mean, seriously, running into each other? …But I can attest, my 20yro Arabian mare and 9yro miniature horse (especially her) are every bit as smart, if not smarter, than the shetland sheepdog we had for 13 years. They’re just different smart. The Arab picks up on patterns and training as fast if not faster than the sheltie did (3 repetitions is all she needed for certain ground tricks) and the mini–not so interested in being obedient–picked up on other patterns that were to her benefit, like how to open gates…sneak food…and otherwise cause mayhem.
Wow, that’s cruelly irresponsible. A good friend of mine in college used work at the Rutgers stables. The horses that carried the Scarlet Knight (the mascot) were retired police horses. I think you could have set of firecrackers in front of those animals and they’d just snort and give you the stinkeye.
I have seen a scared deer run into a somewhat flexible wire mesh fence and still end up killing herself. It hit the fence head first, bounced off, and then laid on its side with it’s eyes open and it’s tongue sticking out, shook a little, then died.
Relevant to the original topic, there was a horse a few years ago who was jumping around an upper level cross country jump course who misjudged a ditch and wall combination, jumped down into the ditch, and slammed into the wall, breaking its back. There was some debate about the construction of the obstacle, as the ditch was somewhat shallow compared to the width – the horse thought it was supposed to jump down and then jump the fence/wall part but didn’t make it.
Horses can be chuckleheads, for sure, and there’s not much stupider than a prey animal in a blind panic, but they do have some problem-solving abilities (some more than others) and, like dogs, have complex social interactions. Like dogs, horses learn what they are and aren’t supposed to do, and will sometimes wait until you aren’t looking to do something forbidden. They can be clicker trained and taught tricks like dogs. Their upper lips are prehensile and, like most things, can be used for evil – horses are notorious for letting themselves out and going roaming around the farm, or opening the feed room door to look for goodies (always, always lock your feed room door with a horse-proof latch!). A friend described her horse looking at a feed bin over the fence that he couldn’t quite reach in the trunk of her car and carefully sliding the towel underneath the food pan towards himself until he could reach the food.
Speaking of upper level eventing, you can practically see these horses think in midair – they may jump into a combination obstacle and have just a couple seconds to figure out where to put their feet as they jump, land, jump again immediately, turn, and jump another large obstacle just a couple strides later. I think this is a combination of physical agility and the ability to make decisions very rapidly – the horses adjust their own stride and jumping effort to respond to the next element. The enormity of this calculation is apparent when a horse misjudges. Of course, not many horses can do the upper levels for some combination of physical and mental limitations.
My aunt had such a horse once. One day the family returned to the farm from a trip into town to discover that this horse had opened the pasture gate, opened the sliding-glass door into the house, and was in the kitchen trying to drink a bottle of Dr. Pepper (apparently a trick his previous owner had taught him). He had NOT managed to remove the bottlecap. Oh and the goats–ever the opportunists–had followed the horse into the house and were standing around on all the furniture. 
Also worth noting are how highly trained dressage horses are–exact sort of dance routines, where to put each foot at according to very subtle cues from the rider. No room for error. It’s pretty amazing.
That’s awesome. I can’t believe the goats didn’t figure out the door first, though.
Humans do stuff dumber than that all the time. And at least horses don’t put it on YouTube afterwards.