What is Water Moccasin Snake Toxicity?
The water moccasin, also known as the cottonmouth, is a type of semi-water-dwelling snake that lives primarily in the Southeastern United States and West Texas. It gets its names from the white coloring inside its mouth and its tendency to live near sources of water. Cottonmouth snakes belong to the Crotalinae family of pit vipers which includes rattlesnakes and copperheads. Similar to other pit vipers in North America, you can identify them by their oval-shaped pupils, triangle-shaped heads, heat-detecting pits, and either a rattle or a single row of belly scales near the base of their tail.
Their venom is used to help them catch and digest their food and can be harmful to humans. Water moccasins usually eat things like fish, turtles, and small mammals, but they might bite a human if they feel threatened or disturbed. While there’s limited information specifically about how to evaluate and treat bites from cottonmouths, this article examines cottonmouth bites within the broader context of bites from other pit viper species.
What Causes Water Moccasin Snake Toxicity?
Pit vipers, a type of venomous snake, aren’t naturally aggressive. They usually only strike in self-defense, or if they feel threatened. Bites from pit vipers typically happen by accident, mostly when people are either handling snakes incorrectly, or when they come across snakes unexpectedly during outdoor activities.
According to one study of snakebites in North America, about half of all snake bites happened to people’s lower bodies, like legs and feet. Interestingly, 27% of those bitten were not wearing shoes at the time of the bite.
The risk of experiencing a severe reaction to the snake venom, known as envenomation, is higher in some situations. For example, if someone doesn’t get to a healthcare facility until more than six hours after the bite, if the patient is a child under 12, and if the snake that bit them was a particularly large one, the risk is higher.
On a positive note, bites from cottonmouth and copperhead snakes, which are types of pit vipers, are less likely to result in severe reactions to the venom.
Risk Factors and Frequency for Water Moccasin Snake Toxicity
In the US, venomous snake bites are most often caused by snakes in the Crotalinae family. The information specifically about cottonmouth snake bites is limited. According to records from the North American Snakebite Registry and the Toxicology Investigator’s Consortium, there were 31 reports of cottonmouth snake bites between 2013 and 2017. Typically, these bites occur on the lower part of the body, and the main symptom is swelling. About 19% of the victims experience stomach issues and another 19% suffer from blood clotting problems. Most victims, around 84%, are given antivenom treatment, and over half of them have to stay in the hospital for more than a day.
According to data from the National Poison Data System in 2017, there were 4071 venomous snake bites reported. The breakdown of these bites is as follows:
- 2035 were from copperhead snakes
- 753 were from rattlesnakes
- 255 were from cottonmouth snakes
- 1,028 were from unknown types of Crotalinae family snakes
Of these total snakebites, there were two fatalities. One was caused by a rattlesnake and the other by an unidentified Crotalinae snake. Among the cottonmouth snake bites, 242 were treated at healthcare facilities. Out of these, 122 patients had moderate outcomes, 10 had severe outcomes, but fortunately, there were no fatalities.
Signs and Symptoms of Water Moccasin Snake Toxicity
When someone gets bitten by a snake, doctors first make sure they don’t have any life-threatening conditions. After that, doctors ask about when and how the bite happened and if they can describe the snake. They also look at where the snake bite is on the body. Common signs of a venomous snake bite may include:
- One or more fang marks
- Soreness
- Redness
- Bruising
- Swelling that keeps getting worse
- Nausea
- Vomiting
- Blood clotting issues
- Other signs that venom is affecting the body
Sometimes, patients bring the snake with them, which helps doctors know if the snake is poisonous or not. But, generally, it’s not a good idea to try and catch the snake as this could lead to more snake bites. Even if a snake is dead, it can still have venom that can cause reactions if not handled with care.
Testing for Water Moccasin Snake Toxicity
If you happen to be bitten by a pit viper before arriving at the hospital, make sure the affected area is still while you get to a medical facility. Contrary to some myths, do not use tight tourniquets or snakebite kits designed to remove venom. These methods are not effective.
Once at the hospital, doctors will first check your airway, breathing, and heart function. While it’s rare, some dangerous symptoms can occur if the snake’s venom triggers a severe allergic reaction or if the bite was near a vein. If you’re in critical condition, the medical team will start treatment to stabilize your breathing, oxygen levels, and blood flow.
Changes in your blood composition are common after a pit viper bite, especially rattlesnakes. These changes are usually less severe if the bite is from a cottonmouth or copperhead snake. A severe bite could result in lower platelet counts, longer blood clotting times, decreased fibrinogen (a protein needed for blood clotting), and higher levels of specific compounds that indicate blood clotting activity. These changes can resemble a condition known as disseminated intravascular coagulopathy (DIC), which involves abnormal clotting and bleeding. Even so, significant bleeding or clot formation is rare in snakebites. These blood changes might come back several days after treatment, and need further study since our knowledge about this is fairly limited.
A snakebite victim usually needs to be watched in the hospital for about 8 hours. If there are no physical signs or lab test results indicating venom injection during this period, it’s considered a “dry bite” – meaning no, or very little, venom was injected. In this case, you can be sent home with instructions on what to do if conditions change. However, if progressive soft tissue injury becomes apparent, overnight hospital observation is advisable. Anyone getting antivenom needs to be admitted to the hospital. When a snakebite happens, medical staff will continuously check the affected area. They’ll note any changes in the sensation and blood flow in the limb, the degree of swelling, and the furthest point from the bite where the patient feels pain. The bite area and other parts closer to the body compared to the other side of the body can also be measured for reference, but there’s no agreed-upon method for doing this.
While there are similarities between snakebite symptoms and compartment syndrome (a painful condition where pressure within the muscles builds to dangerous levels), compartment syndrome is rare in snakebite cases. This complication is most likely to come up with severe rattlesnake bites that cause muscle tissue death.
Treatment Options for Water Moccasin Snake Toxicity
If you’ve been bitten by a snake, the best course of action is to keep the affected area still and immediately seek medical assistance. Old wives’ tales suggest remedies like sucking out the venom, applying electricity, using tourniquets, or putting ice on the bite. In reality, these methods aren’t helpful.
When you reach the hospital, the medical team will look after your wound and update your tetanus immunization if necessary. They might lift up the bitten limb to reduce swelling and discomfort. After a cottonmouth snakebite, doctors typically watch patients for 8 hours. If no symptoms or blood abnormalities appear within this period, you can safely return home. However, if signs of snakebite poisoning begin to show, you’ll need to stay for longer monitoring.
In some cases, patients start showing severe swelling, blood toxicity, or overall body symptoms. In such situations, an antivenom treatment becomes necessary. In the United States, two types of antivenom are commonly used. The first one, Crotalidae polyvalent immune Fab, is made from the antibodies of sheep exposed to the venom of four North American pit vipers. The second antivenom, Crotalidae Immune F(ab’)2, comes from horse antibodies exposed to the venom of snakes from South America. It’s worth mentioning that the second antivenom hasn’t been tested for cottonmouth snakebite poisoning, so how well it works in these cases remains unknown.
The amount of antivenom used depends on the severity of the symptoms. The antivenom treatment can halt the progression of the symptoms but usually doesn’t reverse the effects completely. If the snakebite causes excessively dangerous bleeding or shocks, immediate control of these conditions becomes vital.
In rare instances, snakebite poisoning can cause compartment syndrome, a severe condition where increased pressure in a muscle compartment (a section of your body housing muscles and nerves) can compromise circulation and function. This is usually managed with more doses of antivenom. Surgery is a last resort option, usually reserved for cases where the pressure remains high despite adequate antivenom treatment or in case of extreme pressure in the fingers or toes.
What else can Water Moccasin Snake Toxicity be?
Usually, people who are bitten by snakes often see the snake, making it easier to determine the cause of their wound. But sometimes, patients don’t see the actual snake. In such cases, it can be a bit challenging to tell if the wound is from a snake bite or some other cause. For instance, two puncture wounds close to each other could suggest a snake bite, particularly from a pit viper. However, it’s important to note that not all snake bites result in two puncture wounds. The wound could be from a different sharp object or even a thorn. Such non-snake bite wounds could lead to a skin infection known as cellulitis, which could resemble a pit viper bite, but they typically look and develop differently over time.
So, when doctors are trying to figure out the cause of such a wound, they might consider these possibilities:
- Arthropod (bug) bite
- Cellulitis
- Wound from damaging a blood vessel
- Wasp sting
- Deep vein thrombosis (blood clot)
What to expect with Water Moccasin Snake Toxicity
Data on the long-term effects of bites from cottonmouth snakes is quite limited. Overall, these bites are generally considered less severe than those from rattlesnakes. They have a lower chance of causing severe, life-threatening symptoms.
In 2017, the US poison center reported 255 instances of people bitten by cottonmouth snakes. Out of these, only ten cases resulted in serious health problems, and no deaths were recorded. A survey of past snakebite cases also revealed that people bitten by cottonmouth snakes rarely needed surgery and that treatment mainly involved controlling the pain and taking care of the wound.
If you’re bitten by a cottonmouth snake, you’ll need to be monitored, your wound should be cleaned and cared for, and the body part that was affected should be elevated. You might also need antivenom. If you show signs of coagulopathy which means your blood’s ability to clot is impaired, or if the pain, swelling, or bruising gets worse, you should get antivenom and may need to be hospitalized.
Data related to bites from copperhead snakes, a snake that is in the same family as cottonmouth snakes, shows that the symptoms normally clear up between 7 and 13 days. It’s important to know that you might experience symptoms for as long as 4 weeks before your limb function fully returns to normal.
Possible Complications When Diagnosed with Water Moccasin Snake Toxicity
Although it’s unusual, there can be serious complications from a cottonmouth snakebite. Information on these cases is limited, so we often refer to data pertaining to another North American snake, the copperhead, which belongs to the same family as the cottonmouth. About 14% of copperhead bites result in blood abnormalities, but it is rare for these to lead to actual bleeding. Coagulopathy, a disorder that affects the clotting of blood, and serious bleeding aren’t common, but there have been a few reported cases.
In the less severe cases of cottonmouth snakebites, the bitten person may experience pain, swelling, and trouble using the affected limb. These symptoms could persist for up to a month post-bite. The use of antivenom to treat these bites can sometimes cause immediate, severe allergic reactions requiring immediate treatment. A study conducted from 1997 to 2010 revealed that about 8% of people who were treated with a specific type of antivenom (Crotalidae polyvalent immune Fab) developed an allergic reaction, and 13% developed serum sickness, a reaction to certain medications or antivenom.
Listed Effects of a Cottonmouth Snakebite:
- Blood abnormalities in 14% of copperhead snakebites
- Rare cases of coagulopathy and serious bleeding
- Limb dysfunction, pain, and edema that may persist for up to 30 days
- Potential allergic reactions (8% risk with the use of Crotalidae polyvalent immune Fab antivenom)
- Serum sickness (13% risk with the use of Crotalidae polyvalent immune Fab antivenom)
Preventing Water Moccasin Snake Toxicity
If someone gets bitten by a pit viper, it’s essential to handle the situation correctly to manage potentially harmful effects from the snake’s venom. Here are some key things to remember:
It’s important not to try to remove the venom from the bite by squeezing it out. This process could lead to more harm than good. Also, don’t apply heat or ice to the wound. Despite common belief, these methods don’t help with the pain or swelling, and it could even make the bite worse.
You should avoid putting on tight or constrictive bandages as well. These can block blood flow and cause harm. Similarly, do not use a tourniquet, a device often used to control bleeding, as it could lead to more damage.
One thing you can do to help with the pain and swelling (also known as edema) is to raise the bitten limb above the level of your heart. This position can help reduce the spread of venom.
It’s crucial to seek immediate emergency care and stay there for observation for at least 8 hours. Even if the bite doesn’t seem serious at first, complications can develop overtime that medical specialists need to monitor.
