The trachea is a flexible and semi-rigid tube and is a part of the upper respiratory system which provides a passage to the inhaled air to enter the lungs. Any obstruction in the trachea can hinder the airflow and needs to be addressed immediately. A soft layer of mucus covers the trachea that has microscopic hair on it. The hair is involved in cleaning the air before it enters the lungs as they trap the particles present in the inhaled air. The trapped particulate matter in the hair is moved back up to the mouth to be swallowed. Clearing this debris is important in disease prevention. Canines unable to perform this clearing mechanism may experience collapsing of the trachea and are most likely to develop infections in the lungs.