Where should either end of the endotracheal tube be located in the dog's airway?

• A. Between the larynx and the thoracic inlet
• B. Within the trachea just above the carina
• C. In the esophagus
• D. In the nasal cavity

Answer: (A)

The key idea is that the endotracheal tube must sit in the trachea to ventilate the lungs and protect the airway. In a dog, the trachea runs from just behind the larynx down to the carina, which sits within the thoracic region. So the tube should be located within that tracheal segment—essentially between the larynx and the thoracic inlet. Sitting in this space ensures a clear airway and prevents air from going into the esophagus or becoming lodged in nasal structures.

To ventilate both lungs reliably, the tip should be just above the carina—the point where the trachea splits into the main bronchi. If the tube is advanced too far, it can enter a main bronchus and only ventilate one lung. If it ends up in the esophagus, no ventilation occurs and gastric insufflation and aspiration risk increase.