Their genetics have sacrificed nearly every aspect of basic resiliency for maximum speed on the plains. Most of the work caring for horses is keeping them from accidentally killing themselves. Full disclosure: I worked as a stable hand as a child in exchange for riding lessons. Will never ever own a horse.
Equus simplicidens lived around 4 million years ago in North America, relying on speed, stamina, and herd behavior for protection from predators like early wolves and big cats. Their survival, much like modern equids, depended on strong social structures and collective awareness. Over time, this lineage spread to other continents via land bridges before becoming extinct in North America. evolved into the distinct species of horses, zebras, and donkeys and where reintroduced into the American continent by humans
Equus simplicidens, also known as the Hagerman horse, lived around 4 million years ago in North America and is considered an ancestor of modern horses, zebras, and donkeys[3][5]. These animals relied on speed, stamina, and herd behavior for protection against predators such as early wolves and big cats[3]. Their survival was supported by strong social structures and collective awareness[3]. Over time, Equus species migrated to other continents via land bridges[4]. They eventually went extinct in North America around 10,000 years ago during the Pleistocene extinction event[1][2][4]. Horses were later reintroduced to the continent by humans in the late 15th century[4].
The wording here makes it sound like we hunted horses for the specific purpose of having sex on them, and honestly, I'd probably be running as fast as a car if that kept happening to me too!
Basically a 900LB Cocker Spaniel that's afraid of it's own farts and will eventually kill every single tree within reach.
I also will never own horses.
To add on why broken legs are fatal: its because horses are so big, that even with a sling, they cannot support themselves well on 3 legs. And lying down is also not an option as their own weight will crush their internal organs if they stay down for too long.
Also, don't they need to run to move food through their digestive tract? Or to force themselves to cough if they have something stuck in their lungs? I think there is some sort of dependency of basic functions that relies on the movement of their lungs/stomach going back and forth while running that they can't easily do if they just stand in one place all day
It's not just horses, all large mammals have this problem from lying down too long. Horses can and do lie down every day, but for short periods of time. It's the extended lying down from illness or injury that kills them.
I mean, humans run around on something that birds would consider knees, and stupidly try to support their entire body weight using only half their legs.
Humans have multiple toes because our ape ancestors used their toes like fingers. Having multiple, separate toes is probably bad for survival unless you're using toes to manipulate tools.
Animals that have distinct toes include apes, geckos, mice, raccoons and similar animals which need them to grip onto surfaces or to manipulate things. There are predators which have separate toes because they're a place to mount claws: eagles, cats, etc. There are animals that have separate toes with webbing between for swimming. But, for a lot of animals, separate toes aren't really useful, so they've evolved away: elephants, rhinos, giraffes, horses, cows, etc.
Spreading the weight around using toes doesn't seem to be a useful strategy. It's also not something that humans do. Human toes are not at the weight-bearing part of the foot. And, while I'm sure toes are somewhat involved in agility, having individual toes doesn't seem to be. In fact, if you look at apes like gorillas and chimps, it's pretty clear that our toes have been getting shorter and less important as we've been evolving as upright-walking creatures who don't live in trees. Instead, the sole of the foot, which used to be much more like the palm of a hand, has been getting longer and sturdier.
If you have separate toes, you have multiple fragile things that can break or be torn off. If you have one mega-toe it's going to be sturdy. That's probably why the heaviest animals have the fewest / smallest toes.