Learn how we investigate why by watching our new video. In this video a coughing horse is having a video endoscopic examination of its respiratory tract. The endoscope is introduced through the nasal passages enabling visualisation of the throat and larynx. The endoscope is further advanced into the trachea where samples of inflammatory material are taken via a tracheal wash. The wash can be examined under the microscope to determine the type and number of cells present which can help in determining the underlying cause of the respiratory inflammation. Often infection is implicated so tracheal wash samples can be cultured for bacteria. If the culture is positive, sensitivity to the antibiotics we have at our disposal can be determined, thus enabling the initiation of the correct treatment.