Water moccasins, also known as cottonmouths, are venomous snakes found throughout the southeastern United States, often near water bodies. Understanding the nature of their bites and appropriate responses helps manage potential risks.
Understanding Water Moccasin Venom and Bite Severity
Water moccasins possess hemotoxic venom, which primarily affects blood and tissues. This venom contains enzymes that break down cellular membranes, leading to localized tissue destruction and inflammation. The immediate symptoms of a bite typically include severe pain, rapid swelling, and discoloration at the bite site, which can progress to bruising and blistering. The severity of these symptoms depends on factors such as the amount of venom injected, the bite’s location and depth, and the individual’s reaction.
The venom’s hemotoxic components can also disrupt blood clotting, potentially causing abnormal bleeding. While systemic effects like nausea, vomiting, low blood pressure, weakness, and difficulty breathing can occur, they are less common than local tissue damage. Fatality from water moccasin bites is rare, especially with prompt medical attention. In 2017, for instance, there were 255 reported cottonmouth envenomations in the U.S. with no deaths reported, although ten cases had serious outcomes.
Some bites may be “dry bites,” where no venom is injected, resulting in milder symptoms. Even without antivenom, many bites primarily require wound care and pain control. However, the venom’s potent proteolytic activity can lead to significant tissue destruction, and in some cases, long-term effects like limb dysfunction, pain, and swelling can persist for several weeks.
Immediate Steps After a Bite
Seek immediate medical attention after a suspected water moccasin bite. Call 911 or your local emergency number immediately, particularly if the bitten area changes color, swells, or becomes painful. While waiting for emergency services, move away from the snake to prevent further bites and remain as still and calm as possible to help slow the spread of venom.
Remove any jewelry, watches, or tight clothing from the bitten limb before swelling begins. Clean the bite wound gently with soap and water, then cover it loosely with a clean, dry bandage. Position the bitten area at or below heart level if possible.
Avoid actions that can worsen the situation. Do not apply a tourniquet, cut the wound, attempt to suck out the venom, or apply ice. These measures are not effective and can cause additional harm or infection. The primary treatment for a venomous snake bite is antivenom, which must be administered by medical professionals in a controlled setting. Antivenom, such as CroFab, works by providing antibodies to neutralize the venom’s effects, reducing pain, swelling, and tissue damage.
Identifying Water Moccasins and Avoiding Encounters
Water moccasins are semi-aquatic pit vipers, typically 30 to 48 inches long. They have thick, muscular bodies and blocky, triangular heads distinctly wider than their necks, with a deep facial pit between each eye and nostril. Their pupils are vertical, resembling a cat’s eye.
Their coloration varies from dark brown or black to olive, sometimes with banded patterns, though adults often appear uniformly dark. Juvenile water moccasins tend to have more distinct reddish-brown bands and bright yellow tail tips. A key identifying feature is the white, cotton-like lining inside their mouths, which they display when threatened.
Distinguishing them from non-venomous water snakes can be challenging, as water snakes can also be dark and flatten their heads to appear more triangular. Non-venomous water snakes typically have round pupils, lack facial pits, and generally have more slender bodies with longer, thinner tails. Water moccasins often swim with their entire body on the surface of the water, unlike most non-venomous water snakes that swim with their bodies mostly submerged. When threatened, water moccasins tend to stand their ground, coil defensively, vibrate their tails, and flash their white mouth, whereas non-venomous water snakes are more likely to flee.
Avoiding encounters involves being aware of their preferred habitats, such as swamps, marshes, lakes, and slow-moving streams. When in these areas, wear appropriate footwear like closed-toe shoes or boots. Do not attempt to catch, harass, or kill snakes, as most bites occur when individuals try to interact with them. Keeping outdoor areas clear of debris, tall grasses, and wood piles can also reduce potential hiding spots for snakes near human dwellings.