An old customer of mine who has been a butcher told me that the organs that look the worst in a horse are the lungs. He did not know the exact reason for this, even if he had some suspicions. It is very interesting to know what horses look like internally. Personally I think that the way the lungs appear has to do with their detoxifying function.

The lungs, together with the skin, kidneys, and the colon are the four detoxifying organs.

In gaseous exchange, gaseous detoxification occurs through the lungs: the horse breathes in oxygen that is taken up by the arterial blood, and breathes out carbon dioxide, that is left by the venous blood.

If one looks at the function of the lungs, they are supposed to cleanse, moisten, and warm the inhaled air. The toughest filtration is done by the nasal hairs while the smaller particles stick to the mucus that covers the mucus membrane in the nose.

The lungs of the horse

The horse breathes in mainly through the nostrils, which is an advantage as prey to be able to take in air through the nostrils, sensing smells at the same time as it grazes. At rest, a normal breath is around five liters and the horse takes about 10-18 breaths per minute so at least 50 liters of air are passing the lungs of the horse each minute.

At heavy exertion, both breathing frequency and the size of each breath increases. During a race, about two thousand liters per minute pass the lungs of a race horse. The breathing in a galopp is connected to the frequency of steps; under large effort during a galopp, a horse therefore takes in about 120 breaths per minute.

In trot, however, there is not such a strong correlation. A trotters breathing frequency under large exertion is lower than that of a race horse, about 90 breaths per minute. The breathing is affected by the headposition and the position that is pursued within mainly dressage: this affects the flow in the respiratory system so that the breathing is more strained.