Additional long-term research will be necessary before those questions are answered with certainty. While there are some therapeutic approaches than can assist the horse with COPD, there is no cure. Nor is there a vaccine that can prevent COPD because it is a non-infectious disease. Before we can discuss just what COPD is and how it functions in a horse, we must understand how the equine respiratory system works. Basically, the respiratory system for equines and other mammals functions to exchange oxygen and carbon dioxide.
Oxygen enters the lungs during inspiration, and carbon dioxide exits with expiration.
Oxygen is the fuel to be burned, and carbon dioxide is the exhaust to be removed. Air enters through the nostrils and passes through the nasal cavity. A horse differs from many mammals in that it is unable to breathe through its mouth. A dog or human in need of additional oxygen, for example, breathes rapidly or pants, with air being taken in through the open mouth. Because of this ability, a dog has very small nostrils.