Endotracheal wash or transtracheal wash is a procedure to evaluate lungs for infection (pneumonia), inflammation, or cancer. For the endotracheal wash, the patient is anesthetized and an endotracheal tube is sterilely inserted from the mouth into the trachea. Sterile saline is inserted into the lungs and a sample is then retrieved for analysis (cytology and culture). A transtracheal wash can be performed on larger dogs with only light sedation and a needle catheter is passed directly into the trachea.