What size endotracheal tube is appropriate for a standard 30 - 35 kg MWD?

• A. 7-9 mm
• B. 9-11 mm
• C. 12-14 mm
• D. 5-7 mm

Answer: (B)

Endotracheal tube size is chosen by tracheal diameter, which roughly correlates with the dog’s body size. For a Military Working Dog in the 30–35 kg range, an internal diameter of about 9–11 mm fits best, providing a seal with a cuff while allowing easy placement and adequate ventilation. A smaller tube would raise airway resistance and work of breathing, while a larger one could be difficult to pass and risk tracheal injury. Hence the 9–11 mm range is the appropriate choice.