Your pony’s respiratory rate (number of breaths he takes per minute) should be between 10-24 breaths per minute.
Just as with heart rate this rate will be affected by exercise or pain and illness.
You can measure the respiratory rate of your pony by either watching the movement of his nostrils or the movement of his flank as he breathes in and out.
If your vet comes to see your pony, they probably won’t count the breaths in the same way as this. Instead, they will want to listen to the flow of air, by listening on the windpipe with a stethoscope at the bottom of your horse’s neck. If you have a stethoscope available it is worth trying this for yourself, to learn what your pony’s normal breath sounds are like. You want them to be clear rather than wheezy or crackly.