Injuries & Prevention

Wildlife Encounters – Part I: Rattlesnakes

Wildlife Encounters – Part I: Rattlesnakes

As trail runners it’s all too common we come across wildlife in it’s natural habitat. Many of us secretly hope to encounter wildlife on our runs for that perfect photo opportunity we can quickly post on Facebook. But what would you do if that photo op turned into a confrontation instead?

In just the past month I’ve enjoyed close encounters with several deer, six grey fox, javelina and bobcat. Running before sunrise one morning my headlamp illuminated cat paw prints that were as large as the palm of my hand on a little used trail within five miles of my house (we do have mountain lion in my area but I’ve never seen one in person). I’ve also seen more rattlesnakes on trails this past month than I saw all of last year combined. It was my most recent rattlesnake encounter that made me stop and think.

In the first article of my two part Wildlife Encounters series I’ll address rattlesnake bites.

Running nearly six miles from the nearest trail head I was in a remote rocky section of trail in the McDowell Mountains when I slowed and started walking backward to spot my running partner. As I turned back I stepped within 2”-3” from a coiled rattlesnake’s head. Why it didn’t strike I have no idea (we suspect it had already eaten and was digesting it’s food but don’t know), it also never rattled to give me warning that I was too close. After enduring the normal responses from non-trail runners like, “you’re an idiot, why do you do that?” and “sooner or later they’ll find you’re body (or pieces of it) on a trail somewhere” someone actually had an intelligent response.

Friend: “What would you have done if it had actually bitten you that far from help?”
Me: “Oh, I would have…um…um…I don’t know.”

So I did some research and here’s what I discovered.


Rattlesnakes will normally give plenty of warning that you’re getting too close so you can redirect around them. But what should you do if you are bitten? To find the answer I asked a leading expert, Jeremy Joslin, MD, FAWM (Fellow of the Academy of Wilderness Medicine). Dr. Joslin is director of the Wilderness & Expedition Medicine program at the State University of New York: Upstate Medical University.

From Dr. Joslin:

Couple things to know about envenomations as a preface:

  • About 20% of bites are “dry bites” where the snake strikes and even breaks skin, but doesn’t inject any venom. People speculate if this is teleological (snake doesn’t want to waste his venom, since it takes much caloric energy to replace spent supplies), accidental (snake was surprised and didn’t have enough time to trigger venom glands to squeeze down), or intentional (snake can tell the difference between warning an enemy and killing prey for food and only uses venom for the latter whenever possible).
  • Everything we’re discussing in this article is with respect to crotalids only (pit vipers such as the rattlesnake) and not coral snakes (the elapids which only consist of the coral snakes in the USA).
  • The venom of a pit viper is formulated to necrose (kill) local tissue and basically digest it. This is in contrast to the elapids who’s venom is primarily neurotoxic (which doesn’t do much harm local to the site, but spreads to the brain and heart and stops them from working). So, a large dose of pit viper venom in a small limb will cause significant pain, swelling, redness, and basically starts to digest the muscle and soft tissue in that limb which releases chemicals normally found inside of a cell, but when the cells die, their contents get spit out into the circulation and poisons the person eventually. The venom also starts killing off red blood cells and platelets so people can start to bleed to death internally. In contrast, a small dose of venom to a large limb will cause the same pain, redness, swelling, etc but the amount of cell death and poisons released isn’t too much for the larger body to handle, and can clear those poisons from inside the cell as they’re generated.


This is NOT a happy rattlesnake.

Questions and Answers:

Trail Running Club: If bitten several miles from help and alone or with only 1-2 other people who can’t carry a person out what immediate actions should they take?

Dr. Joslin: It depends on size of person and significance of bite. So a large male runner bitten by a smaller snake, might be fine walking those miles back to the road/car, and only experience pain on the way. His body would likely be able to handle the venom and intracellular chemicals released. But…a small female bitten by a large snake might become ill much faster and might do better not walking on that leg, but waiting for someone to get help. It’s a big judgment call. What would I do? I’d probably try to relax and better assess the situation. I might take off my pant leg and check out the bite. If it’s not starting to swell or only hurts mildly, I’d probably hike out. The balance of hiking out versus staying put is that movement will cause the venom to spread more. This is usually not a problem for pit vipers, but becomes a big problem for elapids.

Trail Running Club: Are there things people should not do, like cut and suction or other common “myths”.

Dr. Joslin: Unfortunately, there is no specific field treatment for pit viper envenomations. Sucking (with a commercial venom extractor or otherwise) provides no real, measurable reduction in venom. Neither does cutting, digging, squeezing, etc. There’s lots of studies done with fake venom and dyes to figure this out. A splint or some way to reduce movement of the affected limb is prudent, but not really a treatment. The treatment is anti venom as soon as possible (if it’s needed at all). The AHA released an update to their first aid recommendations stating a compression bandage is recommended. This was bad advice from them, and every expert in the field disagrees with it. The AHA was lumping in elapids and crotalids into the same group, which is pretty ignorant when recommendations are basically the opposite for the two (since their venom is so different).

Trail Running Club: No one wants to call for air rescue if they don’t have to. Should a person bitten by a venomous snake attempt to hike 5-6 miles to a trailhead or just call immediately if they have a cell phone signal and wait?

Dr. Joslin: Small female and big snake with early signs of redness and swelling? Call for rescue ASAP (even air). Large male and small snake or no early signs of significant envenomation? I’d probably try to self-evacuate. It’s hard to describe a judgment call to a group of readers, I know. Personally, I’d give the situation a few minutes for the dust to settle, and assess the degree of envenomation and formulate a plan. Minutes of purposeful assessment shouldn’t make a big difference in outcomes, except to save resources and money related to a possible rescue.

Trail Running Club: Is there a time limit that if you can’t get to a trail head for help in a certain amount of time a snake bite victim should call for air rescue or does time have nothing to do with it and it’s certain symptoms they should watch for instead?

Dr. Joslin: Certainly, if there’s significant symptoms, or signs that this was a real envenomation in a small limb or small person, hours would make a difference. Not sure how much of a difference minutes would make. I’d prefer to let the symptoms guide the speed and urgency of evacuation.


After extensive internet research and contacting Dr. Jeremy Joslin there are a few things to remember.

  1. The best rattlesnake first aid is actually prevention. In most every rattlesnake encounter you will have ample warning to redirect your path.
  2. There is no specific field treatment when it comes to rattlesnake (pit viper) bites, every bite should be analyzed on it’s own circumstances of human size verus snake size, amount and suddenness of swelling etc.
  3. Remove rings, watches and other items that might severely restrict blood flow should the bite area start to swell.
  4. Take a few minutes to formulate a plan and stay as calm as possible.
  5. Pain, redness and swelling in the bite area is not an indication of bite severity.
  6. Research has proven the “cut and suck” provides no reduction in venom.

About Jeremy Joslin, MD, FAWM

Full bio:


Jeremy Joslin, MD, FAWM is a board-certified emergency physician with experience and training in the wide spectrum of prehospital medicine from austere wilderness medical support to urban EMS & Disaster response. As the director of the Wilderness & Expedition Medicine program at the State University of New York: Upstate Medical University, he trains other emergency physicians to provide operational medical support in wilderness & expedition settings while he maintains a research focus in endurance and heat-related illnesses.

He has worked expeditions and events in remote Utah, the Sahara Desert, and the Gobi Desert; and provides ongoing event medical direction for local & national endurance races, as well as other mass-gatherings and events.

Dr. Joslin provides educational and operational support as an EMS Physician, and is available for medical direction to local fire, EMS, and law enforcement agencies as well as for endurance races, mass-gathering events, expeditions, or search and rescue operations around the world and in the most austere environments. Please do contact him to arrange for these services. (* Licensed in the states of New York and Utah)

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