Which artery is located inside the armpit?

• A. Behind the knee
• B. Inside armpit, both sides
• C. In the neck
• D. In the base of tail

Answer: (B)

Inside the armpit is the axillary artery, a major vessel that runs through the axilla to supply the shoulder and forelimb. In dogs and cats there are axillary arteries on both sides of the body, one for each forelimb, so it makes sense to say it’s located inside the armpit on both sides. The axillary artery starts as a continuation of the subclavian artery and becomes the brachial artery as it travels down the limb. The other locations describe arteries in different regions (behind the knee—the popliteal artery; in the neck—carotid/subclavian areas; at the base of the tail—caudal arteries), which is why they aren’t correct for the armpit.