26/11/2020
HORSE'S RESPIRATORY SYSTEM -
DID YOU KNOW THESE TOP 10 FACTS?
1. Horses can only breathe through their nose. During exercise, it becomes twice as difficult for horses to move air into the lungs, with 50% of the total resistance in the upper airway originating in the nasal passages.
2. One Breath = One Stride. At a canter and gallop, horses take one breath perfectly in time with one stride. This is referred to as respiratory-locomotory coupling. Anything that affects the horse’s breathing has the potential to shorten its stride.
3. The amount of air moved in and out of the lungs increases in direct proportion to how fast the horse is running. If a horse runs twice as fast, it must move twice as much air in and out.
4. When horses inhale during exercise, about 90% of the resistance to air movement is in the upper airways: Nostrils, nasal passages, larynx and trachea. The nose is a major contributor to the resistance.
5. Tightening a horse’s girth too much will affect performance, not because of constricting the chest and preventing the lungs from expanding, but because it decreases the effectiveness of the muscles around the front of the chest and shoulder that move the forelegs. More strides result in more breaths.
6. During canter and gallop, horses do not breathe by expanding and contracting their chest. They expand and contract the chest when breathing at rest, when walking and trotting, and when blowing hard after exercise. During a fast canter and gallop, all air movement comes from movement of the legs and diaphragm. The air moves in and out along the lines of a syringe; with the stiff wall of the syringe representing the chest and the plunger the diaphragm.
7. Horses hold their breath over jumps and do not breathe again until they land; then, they begin by exhaling or breathing out.
8. You cannot train the respiratory system of the horse. The amount of air moved in and out by an unfit horse at a fixed speed will be the same as when that horse is fully fit.
9. When galloping, the blood pressure in the blood vessels within the horse’s lungs (referred to as pulmonary blood vessels) is 4-5 times greater than when at rest.
10. Increased pressure puts stress on the very thin walls of the blood vessels and can cause them to rupture. This bleeding, also referred to as exercise induced pulmonary hemorrhage (EIPH), occurs deep within the lung tissues. Horses that bleed rarely show blood at the nostrils.