According to OutdoorHub.com, there are “over 20 species of venomous snakes in North America” and “at least one species of venomous snake in every (US) state except Alaska,”
How does that make you feel? Like switching your vacation to Alaska?
All of us, children of the television that we are, have been raised on images of the snake as a killer: hissing rattlesnakes rearing back to strike, sinewy assassins sliding out of briefcases full of money, victims clutching at their throats as the poison takes hold.
TV exaggerates, oversimplifies, distorts, but it doesn’t invent terror – it exploits it. Evolution has programmed into each of us an extremely wise fear of snakes. Bites may be relatively rare but sometimes the worst does happen and symptoms of venomous snakebites can include convulsions, stomach pain, difficulty swallowing, headaches, shock and paralysis (1).
The only reason death isn’t listed is because death isn’t a “symptom.”
There’s no doubt snakes are the stuff of nightmares and there are some serious nasties in North America. If you run into a copperhead, cottonmouth or diamondback in the wild (I know, they’re even named like serial killers) you’ll want to know how best to protect yourself. This article will give you the lowdown on venomous snakes in the US.
- General Guidance
- Coral Snakes
- Snake Bite First Aid
- Dog snake bite symptoms and treatment
Please include attribution to https://rollingfox.com with this graphic.
The US National Park Service, suggest that to avoid being bitten by a snake whilst hiking you should:
- Stick to designated walking and biking trails
- Avoid placing your hands or feet where you can’t see them
- Keep all pets on a leash (dog owners will be fully aware of their propensity to literally sniff out trouble, often for their owner!)
They also note that if you do see a snake you shouldn’t “provoke it.” Who would be stupid enough to provoke a snake, you might think? Maybe the kind of person who’s likely to need…
First Aid for a Snakebite
If you or someone you know is bitten by a snake the Park Service advise:
- Getting away from the snake as a first priority, to avoid further bites
- Staying calm (good luck with that, you might think! Note, though, that “activity can increase venom absorption” (2))
- Keeping any affected limbs lower than the heart
- Seeking medical help as swiftly as possible, even if there are no symptoms
All snakes are different, of course, and the above offers only general guidelines. Read on for an in-depth breakdown of common venomous snakes in the US, how to spot them, how to avoid them and how to deal with bite symptoms.
Rattlesnakes are classed as “pit vipers” and account for a significant proportion of venomous snakes in the US. Depending on your position on various zoological quibbles around what constitutes a “true” rattlesnake, 14 of the 21 currently accepted venomous snakes in the US are rattlers (3). Even a mathematical dunce (like me) can tell you that’s two-thirds.
Rattlesnakes are named in honour of their signature feature: a tail that makes a rattling noise to warn those they perceive as a threat. LiveScience point out that young rattlesnakes have no rattle but are “as dangerous as adults” and that “some adults may lose their rattles,” so trekkers can’t rely on the rattle alone to identify the snakes.
Another identifying feature rattlesnakes share is a triangular-shaped head (4), however, since rattlers can vary greatly in length and colour from one species to another, it is worth looking at the identifying features of the major rattlesnakes in turn.
National Geographic class the Eastern Diamondback, which can grow to up to eight feet and weigh 35 pounds, as “the largest venomous snake in North America.” As its name suggests the snake is found in the eastern states but it would perhaps more accurately be named the southeastern diamondback, since its habitat ranges from “southern North Carolina to Florida and west to Louisiana.”
Sharp and well-defined black diamond patterns offset by yellow borders” (5), in combination with its sheer scale, are a means of identifying the eastern diamondback.
Western Diamondbacks are a few feet smaller than their eastern cousins and tend to have paler colours. They range across the southeast of the US, Texas, New Mexico, Arizona and California (6), and have a reputation as “the most aggressive of the rattlers” (7).
Estimates of the deadliness of the diamondback bites range from 10-30% (8) so if you see a large snake with diamond patterns and a rattle give it a wide berth!
The mojave rattlesnake has a similar range to the western diamondback but, as its name suggests, is very much a creature of the desert (9). If you are hiking in the Grand Canyon or another dry, sandy expanse in the southwest watch out for greenish coloured snakes between two to four feet long (10).
Mojave’s are said to possess particularly potent venom, perhaps because their venom produces different effects to most rattlesnake bites. Most rattlesnake venom is hemotoxic and produces localised effects like swelling and bruising, but mojave venom also results in neurologic effects, such as breathing difficulties (11).
The timber rattlesnake has a particularly genus name, Crotalus Horridus, and is likely to have you exclaiming horridus! if you are bitten by it. It is the third biggest rattler in the US, with an average length of 76-152 cm, and can be found in the majority of eastern states; Florida is a notable exception.
The timber rattlesnake is reluctant to bite, often rattling for prolonged periods before doing so, but can certainly do damage when it does let loose. The effects of the bite can vary by region. According to Reptiles Magazine “in the more extreme northeast, the venom is primarily hemorrhagic, while venom from the more southern specimens contains significant neurotoxin. Snakes in the middle may have elements of both, making their bites extremely toxic.”
The tiger rattlesnake is named in honour of the dark bands and tinges of orange that recall the big cat (12) but has the smallest head of any rattlesnake. This limits the amount of toxicity in its bite, making deaths from a tiger rattlesnake extremely rare (13).
The snake has a limited range. It is only found in certain areas of Arizona, particularly along the Mexico border, so keep your eyes peeled for “tigers” if you’re hiking in that area!
Prairie rattlesnakes are found in the central US, with their territory extending from Canada in the north to Texas in the south and from Idaho in the west to Iowa in the east (14). The prairie rattlesnake is not considered as dangerous to humans as diamondbacks, but neither is the snake as placid as some would like to think.
Contrary to myth the prairie rattlesnake doesn’t share tunnels dug by prairie dogs, it kills and digests the dogs and then lives in their tunnel! (15)
The prairie rattler is considered a medium-sized rattlesnake (roughly two to four feet in length) and has relatively small venom glands so, while technically capable of killing humans with one bite, the snake is one of the less lethal ratters (16).
In theory rattlesnakes should be one of the easiest snakes to avoid since their unique warning system, the tail rattle, is so pronounced. Rattlesnake tails can produce warning sounds of up to 80 decibels – as loud as a freight train at 15 feet (17) – so if you hear a rattle in the wild try to move away from the sound (18)
Rattlesnakes do not prey on humans. Indeed, expert sources affirm that the snakes will “do everything they can to avoid contact with humans” (19).
That beings said, bites do happen – and they are a serious business. All rattlesnakes are venomous and their bites have the potential to kill. Healthline.com list the primary symptoms of rattlesnake bites as:
- severe pain
- drooping eyelids
- low blood pressure
- tiredness or muscle weakness
If you believe you may have been bitten by a rattlesnake head to your nearest emergency room as a matter of urgency
Copperhead snakes are another type of pit viper and are named in honour of their most striking feature, their copper-red colouring, which is often most obvious on their head. Copperheads also have an hourglass pattern to their markings that can help identify them (20).
Copperheads are classed as medium-sized snakes, with an average length of 2-4 feet, and, according to Live Science, are the most likely to bite of any North American snake. This may be due to an unusual behaviour of copperheads. “Unlike many venomous snakes that usually slither away when humans are around,” artofmanliness report, “copperheads will freeze in place, often resulting in humans stepping on them and getting bitten.”
As this map highlights copperheads are found in a block of US states in the southeast corner, reaching as high as New England and as far west as Texas.
There is good and bad news here. Copperhead bites have a reputation for being extremely painful, an obvious negative, however, on the flip side, their bite “is almost never fatal to an adult” (21) so you should survive.
Look out for the following symptoms of a copperhead bite (22):
- immediate pain
- change in skin color
- low blood pressure
Head for an emergency room as quickly as possible if you think you’ve suffered a copperhead bite.
You may know the cottonmouth by its other name, water moccasin. Both names provide clues to main characteristics of the snake. It is “semi-aquatic” (23) – comfortable on both water and land – and its mouth has a distinctively white interior. This “cotton” mouth is usually shown to those who threaten the snake to try and intimidate them.
The cottonmouth is also known to let a “musky secretion rip from their anal glands” when threatened (24). As if you didn’t have enough reasons to run away from snakes already; this one farts, too!
Cottonmouths have a similar geographical distribution to copperheads but don’t range as far north (25). If you are moving through wet terrain in the south east, marshes, creeks, etc, keep your wits about you.
Like many snakes cottonmouths don’t go out of their way to bite people. That is why threat behaviour, exposing their mouth and stinking the place out, is part of their evolutionary arsenal.
If they do bite they are likely to do more damage than their neighbours, the copperhead. “An adult Cottonmouth can kill an adult human, because it delivers enough venom of stronger proteins that break down more tissue and blood cells, and can cause systemic bleeding” (26) though effective anti-venoms are available.
Symptoms of a cottonmouth bite include:
- immediate pain and symptoms
- change in skin color
- low blood pressure
Coral snakes can be extremely small, less than 50cm long and as slender as a pencil, but don’t be fooled by their size – corals “have the second-strongest venom of any snake,” behind only the black mamba (28).
Fortunately, the diminutive stature of coral snakes limits the size of their bite so, while they are more toxic than rattlesnakes, they are generally considered less dangerous.
Coral snakes have distinctive colouring: alternating bands of yellow, red and black (29). Note that the red and yellow bands touch each other. Similar looking snakes are out there but their red and yellow bands do not touch. Fortunately, a catchy rhyme has been created to help you remember how to pick out a coral snake from non-poisonous imposters!
Red on yellow, can kill a fellow
You’d be advised to run this rhyme through your head from time to time if you’re hiking in woody, sandy or marshy areas in states along the south east of the US. Check out this map for more information on states in which you can expect to encounter coral snakes.
Symptoms of coral snake bites include (30):
- Stomach pain
- drooping eyelids
- change in skin color
- stomach pain
- difficulty swallowing
The severity of some of these symptoms highlights the potency of a coral snake’s venom. It should also be noted that some of the symptoms can set in after a delay of several hours.
If you think you have been bitten by a snake with bands of red and yellow head for your nearest ER as soon as possible.
Snake Bite First Aid
It is worth reiterating that none of the snakes in this list prey on humans. Snakes will only bite if they feel threatened or if they are startled – excellent news for those who could get through life without knowing what it’s like to have rattlesnake venom attacking your nervous system.
The best protection against venomous snakes is, of course, to avoid being bitten by them, so let’s revisit the National Park Service advice on avoiding bites:
- Stick to established trails
- Avoid placing your hands or feet where you can’t see them (especially into long grass or the rocky crevices snakes like to call home)
- Keep pets on a leash
Of course, accidents do happen. What should you do if you suspect you’ve been bitten by a venomous snake?
First things first, Don’t Panic! At least, try not to… Between 7000 and 8000 snake bites occur in the US each year but “only 7- 12 deaths are reported annually” (31). The odds are in your side and it is known that a more active (read “anxious”) nervous system spreads venom round the body at a faster pace. Panicking will only make things worse.
Antivenom is commonly used as a treatment for serious snake bites and is extremely effective. “How quickly can I get to an emergency room?” should be the first question you ask yourself after a bite, particularly since when it comes to administering the antivenom “time is of the essence. The sooner you can get treatment, the less damage will be done.” (32)
There are no hard and fast rules regarding how quickly a snake bite will kill. This depends on how much venom is injected in the bite, whether it is hemotoxic, neurotoxic or a mixture of the two, and the body size and weight of the victim (33). Indeed, some venomous bites will not require antivenom at all, just cleansing of the wound and a tetanus shot (34).
The chances are, if you can get yourself to ER within a reasonable timeframe you will survive to tell the story.
Wilderness First Aid Treatment
If you’re out on the trail when you suffer a bite it may take a while to get to ER. If this is the case, first aid for the bite will assume greater importance.
While walking or waiting for medical evacuation Art of Manliness note that you can mitigate the effects of a snake bite by:
- Washing the bite with soap and water to remove as much of the snake’s spit as you can (as soon after the bite as you can)
- Staying calm and keeping the bitten area below the heart to slow the flow of the venom
- Take off any rings or watches in case venom causes the flesh to swell and circulation becomes cut off
If it is going to take more than 30 minutes to reach an emergency room you may want to consider the following:
- Tightly wrapping a bandage two to four inches above the bite. This is very much a “trade off” treatment – it can slow the flow of venom to the rest of the body but lead to increased tissue damage in the bitten area
- Use the suction device from a snake bite kit to draw the venom out of the wound.
The Things You Shouldn’t Do
How many cowboy movies have you seen where someone cuts across a snakebite and sucks out the poison? That’s TV up to its old tricks again, perpetuating myths.
Wildbackpacker.com and the CDC highlight almost as many don’ts as do’s when it comes to snake bite first aid.
Contrary to perceived “wisdom” you should never:
- Cut across snake bite marks and suck out the poison as if you were John Wayne – this increases the risk of a wound infection and gives the venom a second means of accessing the bloodstream (via the mouth).
- Try to trap or kill the snake. The doctors in the emergency room don’t need to see the snake to treat a victim and they’ll likely be treating two victims if you go after a snake that’s already lashed out
- Apply a cold pack since it reduces healthy circulation to the infected area
- Use alcohol as a makeshift painkiller. It could render the victim incoherent when they’re trying to describe the snake that bit them to ER staff or increase their confusion and anxiety.
Dog snake bite symptoms and treatment
Dogs may be a man’s best friend but they are not a snake’s best friend. Those curious, super-powered noses are excellent at sniffing snakes out and a bite is often an impetuous pup’s reward for getting too close.
Statistics suggest that dogs are “20 times more likely to be bitten than people, and 25 times more likely to die” from a snake bite (35). Few things are as upsetting as a pet in distress so how can dogs be protected from snakebites?
As ever, preventing a bite from taking place is the best protection. Keeping dogs on a lead while on walks may seem stifling but will greatly reduce their ability to disturb snakes – particularly if you stick to established paths (where snakes should be more visible) and pull the dog back immediately if it shows a desire to dig under logs, push into long grass or investigate any other areas that may harbour snakes.
PetMD also suggest that you:
- Keep nighttime walks to a minimum since many snakes are nocturnal.
- If you hear a rattlesnake, keep your dog at your side until you locate the snake; then move away.
Vetinfo highlight a number of symptoms that may indicate a dog has suffered a snake bite. These include:
- Fang marks and or localised swelling, bruising or redness
- Symptoms that affect the nervous system such as drooling, incontinence, confusion, muscle and seizures/partial paralysis
- Respiration problems/lethargy
Wilderness First Aid
First aid and medical treatments for snake bitten dogs closely resemble those for humans. Rather than rushing your dog to ER (where it is unlikely to be welcomed!) you should head straight to a vet where the bite can be professionally treated and anti-venom applied, if necessary.
Out on the trail it is advised that you:
- “Try to identify the snake by taking note of its size, color patterns and the presence or absence of a rattle at the end of the tail” (36)
- Apply a constricting band just above the site of the bite if it is on a limb. This should localise the effects of the bite and ensure that, if the worst comes to the worst, the pet loses a limb rather than its life
- Keep the animal as calm as possible until you get to the vets
- Can a snake bite underwater?
Yes. Cottonmouths can do so and fatalities have been recorded as a result of this (37)
- Can a snake bite through clothing?
It depends what clothing you are wearing. Cotton can disrupt bites. Some say denim is even more effective (38)
- What snake kills the fastest?
The black mamba, not native to the US, has the most potent poison. A single bite can kill a human in less than 30 minutes (39)
- Can a snake bite kill a horse?
Yes. Large snakes, like rattlesnakes, have the potential to kill horses with their bites (40)
- Which snake bite causes neurotoxicity?
Coral snake bites cause neurotoxic effects (41)
- Are snake bite kits effective?
Pumps that attempt to withdraw the poison from a bite are recommended by some sources but considered ineffectual by others. If you have suffered a serious bite you are advised to head to ER regardless of whether you have a snake bite kit or not
- Should you suck a snake bite?
No! This is a myth from the movie
Note: I’m not a doctor and this article should not be taken as medical advice.