Do Horses Breathe like Other Mammals?

Horses do not breathe like other mammals—they only breathe through their noses because they cannot breathe through their mouths. The equine respiratory system functions by inhaling and exhaling through the nostrils. This is thought to perhaps be an evolutionary feature to prevent debris, such as dust and dirt, from entering the horses’ lungs as they run. Their large size makes it so that horses are only able to inhale as their front legs stride, but not as their legs land because their internal organs are proportionately larger than other mammals’. Horses’ lungs would then not be able to expand efficiently to allow oxygen in during landing due to the force that would shift their internal organs.

More about horses:

  • A horse’s teeth appear to continuously grow through its lifetime. The animal is born with its teeth fully formed beneath the gums and they gradually become more visible over time.
  • An average horse’s lung capacity is nearly twice as great as an elite human athlete’s.
  • Horses are physically unable to vomit because the band of muscles that surround their esophagus are so powerful. In fact, if a horse does vomit, it’s generally a sign of a possibly fatal stomach rupture.

Discussion Comments


The horse has a one-way digestive tract, ingesting food at one end and passing faeces from the other. There is no return for food swallowed. The horse has a cardiac sphincter muscle and this muscle stops the horse from being sick. If the horse eats something toxic, the toxins have to work their way through the horse's system. Since the horse cannot vomit, the toxins that are working their way through the system will poison the horse's body. The toxins will ultimately kill the horse. This is why it is so important to feed the correct food and forage to your horse. Do not feed any highly fermentable food stuffs that have gone off.


These are some interesting facts about horses, even though it does seem like a few were left. One example is the intelligence of horses. While they're obviously not the smartest animal on the planet, they have been shown to be quite intelligent, and much smarter than some people give them credit for.

As for some of these listed facts about horses however, these are incredibly interesting. I didn't know that horses couldn't vomit. If that's the case, then what happens to them if they eat something they're not supposed to? Overall, some incredibly interesting facts.

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