Your horse cannot breathe through its mouth

A galloping horse is running flat out, lungs heaving — and its mouth has nothing to do with it.

Horses are obligate nasal breathers. The soft palate sits in a long seal below the epiglottis, effectively shutting the mouth off from the airway. Every breath, resting or racing, goes in and out through the nostrils. It's why a horse can graze and breathe at the same time without choking, and why those nostrils flare so dramatically under effort: they are the only door available.

There's a second oddity on top of it. At canter and gallop, breathing locks to stride. As the forelegs land the gut and diaphragm shift, pushing air out; as the horse extends, air rushes back in. One breath, one stride, like a bellows wired to the legs.

It makes a horse a magnificent runner, and a slightly fragile one.

Why it matters in the yard: anything that narrows the nose or throat matters more in a horse than it would in a dog. Noisy breathing at exercise, a nasal discharge from one nostril, persistent coughing, or distress with flared nostrils at rest are not things to wait out. Dusty hay and poorly ventilated stables load that single airway too — soaking or steaming hay is one of the kindest small changes you can make.

If breathing looks laboured at rest, call your vet the same day. 🐴