What’s the difference between a dog and a horse? Well, look past the more obvious distinctions – the hooves; the mane; the lack of woofing – and you’ll find the two species are actually a lot more similar than they seem.
Humans’ best friends
Of all the species humanity has domesticated over the millennia, dogs and horses undoubtedly stand out from the rest. We’ve grown closer to these species than almost any other – only can compete, really, but they simply like their equine and canine brethren.
But while we’re used to the idea of , we don’t often think of horses as having the same kind of connection to our species. That’s partly because dogs simply express their emotions in a way that’s more readily interpretable to humans: “Dogs jump on us and invite us to play and ,” Elke Hartmann, a researcher in the Department of Animal Environment and Health at the Swedish University of Agricultural Sciences in Uppsala and first author of into horse-human bonding, told in 2021. “Is that how horses would show attachment? I don’t know.”
Admittedly, the small amount of research that has been done hasn’t found any conclusive evidence that our equine pals feel for us the same way we do them – but neither has it been ruled out. “We just don’t know enough about it yet,” Hartmann said.
Perhaps the problem is that we’re being too human-centric, however. “Horses show similar physiological and behavioral responses to humans as they do to horses,” horse ethologist Renate Larssen. “We know that human-directed friendly behaviors are mediated through the hormone oxytocin […] which plays a role in social bonding.”
Studies have also found that, like dogs, horses a “safe haven”, and stress out when their owner is absent. “However, there was no difference in how the horses responded with their owners or with an unfamiliar person,” Larssen noted, “which means that it may be more due to a generalized positive association with humans than ‘love’.”
But some other clues show just how attuned horses are to our species. In yet another point for the “horses are just three dogs in a trenchcoat” column, they’re the human pointing gesture – an ability so far unknown outside of our little tri-species club. Equally, they’re able to direct our attention to something of horsey interest: they “appeared to use both indicative (pointing) and non-indicative (nods and shakes) head gestures in the relevant test conditions,” found , and “elaborated their communication by switching from a visual to a tactile signal” to get their point across.
, horses between positive and negative facial expressions in humans – they can even by the juxtaposition of a happy voice with a sad face. And they’re sensitive to even more subtle human cues, too: just consider , after all – the horse that had the world convinced he could speak German and perform complex mathematical calculations, but in fact was just a master at reading the body language of the humans around him.
But to really cement the similarities between dogs and horses, consider this: humans may actually be the third wheel in the relationship. Just like our pups, horses like to run and play – and in very similar ways: both species signal their openness to friendship with open mouths and behavioral mimicry. In fact, the two animals are so in tune that they even play like this with each other: “despite the difference in size, the phylogenetic distance, and differences in the behavioral repertoire, dogs and horses are able to fine-tune their actions thus reducing the probability of misunderstanding and escalating into aggression,” concluded .
“It shows how two animals who look and behave so differently can nevertheless manage to negotiate how to play in a way that’s comfortable for both,” Barbara Smuts, a behavioral ecologist at the University of Michigan, told at the time.
“It’s even more noteworthy given the large size difference between horses and dogs,” she added. “The dog is vulnerable to injury by the horse, and the horse has a deeply ingrained tendency to fear animals who resemble wolves.”
Engineered for success
It’s hard to think of any species whose history is quite as as dogs and horses. But while we tend to think of the two species as filling pretty different niches, the truth is that there’s some surprising overlap.
Consider the greyhound, for example: the fastest of all dog breeds, they have been bred to have sleek bodies, powerful hind leg and back muscles, large hearts and lungs, and plenty of other specialized physiological characteristics that help them reach top speeds of up to 72 kilometers per hour (45 miles per hour).
Compare those traits with the thoroughbred horse – generally known as the fastest of all horse breeds, and capable of extremely similar speeds to the greyhound – and you may notice . Big hearts; specialized coats; jacked-up hind muscles – they’re all there, helping the beast perform that same ecological niche (enabling human gambling) as their canine pal.
And that’s barely the start. For almost every role one species has been bred for, so too has the other: if you can’t get your hands on a carthorse, for example, there are huskies and sled dogs; for those who don’t want a guide dog, meanwhile, a seeing-eye horse makes a neat substitute.
“They want to please you,” guide horse trainer Katy Smith told in 2018. “It’s the way they watch you and want to be with you […] Get some panniers and they can also carry your shopping.”
Much like dogs, too, horses come in all different shapes and sizes – and much like dogs, that’s directly due to human meddling. “Domestication has made both species highly successful and widespread all over the world,” wrote Juliane Bräuer, head of the DogStudies Lab at the Max Planck Institute of Geoanthropology, in a 2023 article for .
“Dogs and horses are used for many purposes and undergo extensive training in various human cultures,” she added. “Although horses were domesticated than dogs – about 4,000 years ago – they have also evolved special skills to communicate with humans.”
The fuzzy of it all
Of course, as useful and practical as our domesticated animal friends are, that’s probably not why most of us keep them close to us. We don’t just like petting dogs, we get from it; equally, we don’t just enjoy looking after horses, we gain a from doing so, making both species valuable as therapy animals.
But aside from all that, horses also share some unexpectedly cute characteristics with their canine pals. They get the zoomies, for example; they’re super-social and enjoy hugs and affection; they even like to and create snow Pegasuses.
So is it weird to think of horses as just big dogs? Not really. As we’ve seen, they have quite a lot in common – and for some cultures, that has always been obvious: “in the Ioway language, a horse is called a ‘big dog’,” Bräuer pointed out.
“The link between horses and dogs in Ioway and other Indigenous languages underscores something important,” she wrote. “In some way, one can consider the horse as a big dog – at least one of the very few animals that are willing to form a close relationship with us.”