Cottonmouth (Water Moccasin)

Topic Overview

The cottonmouth, also called a water moccasin, is a poisonous (venomous) snake found in southeastern and south central North America. They leave one, two, or three puncture marks on the skin, but you won't always see any marks.

Water moccasins can be up to 6 ft (2 m) long and have:

• Distinctive white coloring inside the mouth.
• Pitlike depressions behind the nostrils.
• A triangular head with slit-shaped pupils and fangs.
• A single row of plates or scales on the undersurface of the snake, including the tail.

Symptoms of a cottonmouth bite usually appear from minutes to hours after a bite and can include:

• Severe, immediate pain with rapid swelling.
• Discoloration of the skin.
• Difficult or rapid breathing.
• Changes in heart rate or rhythm.
• Metallic, rubbery, or minty taste in the mouth.
• Numbness or tingling around the mouth, tongue, scalp, feet, or the bite area.
• Swelling in lymph nodes near the bite injury.
• Signs of shock.

If you think you have been bitten by a water moccasin, call 911 or other emergency services immediately.