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Snake oil for snakebites (and other bad ideas)

Spring is here.  I don’t say that because of the warmer weather, the blooming tulips in my back yard, or the current effect of the earth’s axial tilt on the Northern hemisphere.  No, in my somewhat warped world of the pediatric ICU seasons are marked by illnesses and injuries with an annual rhythm.  Fall begins with a spike in cases of bronchiolitis, Summer with a near-drowning in a swimming pool.  Winter has arrived when seasonal influenza reappears.  And Spring, well, Spring has several harbingers, including auto vs bicycle accidents, falls from windows, and snakebites.

Sure enough, this week we admitted our first child of the year bitten by a venomous snake who, like most people unfortunate enough to be envenomated by a North American pit viper, has done very well.  This child fell prey not only to our local limbless fauna, but also to one of several common myths or misunderstandings about snakebites that place the victim, rescuer, or both at higher risk for injury and complications.  This post will explore some of the more common mistakes people make during North American snakebite encounters (being limited to snakes native to North America, the following does not necessarily apply to snakes from other areas).

File this post under Science-Based-You’re-Not-Helping-Please-Don’t-Do-That.

Myth #1: You Need to Know the Species / Kill the Snake

North America has around 120 species of snake, over 20 of which are venomous.  With so many species, it may seem important to ID the snake so the docs in the ED can give the appropriate anti-venin.  Fortunately, that isn’t the case.

All venomous North American snakes fall into one of two families, the Elapidae, and the CrotalinaeCrotalinae encompasses most of the venomous species commonly encountered, including the Copperhead, the Cottonmouth (aka Water Moccasin), and all rattlesnakes.  Elapidae, on the other hand, is represented by only two species in North America, both a type of coral snake.

The close evolutionary relationship of these snakes (except the coral snake) means that the venom of all Crotalinae is very similar.  Venom is a mixture of a variety of different enzymatic proteins and low-molecular-weight polypeptides, in the case of Crotalinae including proteolytic enzymes, collagenase, hyaluronidase, phospholipases, RNase, DNase, phosphodiesterase, lactate dehydrogenase, a thrombin-like enzyme, and more.  It’s nasty stuff.

Though people have tried to label certain venoms as “hematotoxic” or “neurotoxic,” the sheer variety of proteins and their broad range of actions make this labeling somewhat misleading.  Symptoms and findings at the site of the bite include rapid swelling, bruising, pain, and erythema, while systemic symptoms include nausea, vomiting, oral paresthesias (odd sensations) including a metalic taste, low blood pressure, rapid heart rate and breathing, a markedly deranged ability of the blood to clot, kidney damage, altered levels of conciousness, weakness, double vision, and more.  The volume of venom and relative proportions of its component molecules vary species to species and snake to snake.  However, since the molecules themselves are so similar (and in many cases identical), a single antivenin is capable of treating the venom from all species within the family Crotalinae.

This fact mean clinicians need only ensure that the bite A) didn’t come from a zoo or private collection containing a non-North American venomous snake, and B) that it wasn’t a coral snake, before selecting which antivenin to administer.

How can a doc be sure someone wasn’t bitten by a coral snake?  After all, it does require a different and difficult to obtain antivenin from the Crotalinae. Here again we are assisted by happy chance.  Coral snakes have a very limited range, and can be ruled out in the majority of states.  In areas where the coral snake is endemic, it is easily identified by its red/yellow/black coloration at a distance.  Even an un-witnessed bite can frequently be distinguished by the symptoms and physical appearance of the bite on arrival.  Furthermore, coral snakebites while very serious are quite uncommon, making up only ~1% of venomous bites.

Physicians almost invariably have all the information they need to treat North American venomous snakebites from knowing the geographic location where the bite occurred and the patient’s history and physical exam.  No snake corpse is required or desired.

What’s the harm in killing the snake?  I’d think this was obvious were it not for the nearly ubiquitous element of snakebite histories that people went out of their way to kill the offending animal (the family this week did exactly that).  The risk of trying to kill a snake is that you can be bitten too.  Of all venomous snakebites, almost half occur while people are trying to kill a snake.  They place themselves at risk for no benefit to the person already bitten. Oh, and people will frequently then bring the “dead” snake in to the ED.  Is it dead?  Probably, but since the bite reflex can remain intact for a short time after death, I’d rather not risk my life on your skill as the Great White Hunter.

The best plan is to get everyone safely away from the snake and call animal control to get the animal away from your home, don’t try to do it yourself, and don’t bring it to the hospital.  Please.

Myth # 2: Most Snakebites are Rapidly Lethal

I remember speaking to a 12-year-old last year who was 2 days out from his bite and doing well, only to find that he still fully expected to die from the bite.  A snake, after all, had bitten him and snakebites kill you!  It broke my heart that I had allowed him to live with this fear for two days.

I should have anticipated his fear, because his reaction is not at all uncommon.  Most parents (and children old enough to know) are terrified when their child is bitten by a venomous snake.  Though entirely justified, their fears and expectations are usually out of proportion to the actual risk.

The lethality of a bite depends on a vast number of variables including the species and size of the snake, the location of the bite, the number, depth, and duration of bites, the first aid given, and the type and rapidity of medical care received.  In general, for Crotalinae envenomations not given antivenin the mortality is a very respectable 5-25%.

Antivenin (Crotalidae) Polyvalent (ACP) was the first antivenin introduced in 1954, and was produced by exposing horses to low doses of venom to induce antibodies against its component molecules.  IgG antibodies, including those now directed against the venom, were then purified from the horse’s blood and this was injected into humans bitten by Crotalinae species.  The antibodies then bind to the various proteins and enzymes in the venom, rendering them inert.  The use of this antivenin reduced the mortality rate from 5-25% down to 0.5%.

Though effective, ACP had a rather high incidence of anaphylaxis (20-25%) and serum sickness (~50%), driving the development of a better antivenin.  In 2000, CroFab was approved.  Derived from sheep serum, containing far less non-human protein, and being made of a Fab fragment, Crotalidae Polyvalent Immune Fab (Ovine) aka CroFab, has been far better tolerated.  Post-release studies have reported anaphylaxis or severe reactions in 0-19%, and serums sickness in 0-23%, and mortality rates are the lowest they have ever been.  CroFab is currently the only Crotalidae antivenin available.

Presently there are around 8000 venomous bites per year in the US, but less than 12 deaths per year, making current mortality ~0.15%, though another 15-40% of victims sustain some form of permanent injury or disfigurement.

In addition to the fact that most bites are from non-venomous snakes, there is another facet to snakebite lethality to think about: the concept of a  “dry bite,” or a bite from a venomous snake without injection of venom.  It’s surprisingly common, accounting for around 25% of Crotalinae bites and ~50% of coral snake bites.  Given the high rate of dry bites from venomous snakes, large number of bites from non-venomous snakes, and the rather high side-effect profile of even our newest antivenin, it’s reasonable to ask who should get antivenin.

If you have symptoms of envenomation, you need antivenin, period.  However, symptom onset can be delayed, occasionally by hours.  If someone arrives in the ED with a bite but no symptoms other than a couple of small holes, it is reasonable (and standard of care) to watch them in the ED without antivenin.  Should symptoms begin, antivenin should be started immediately, but if there are no symptoms after 12 hours, it is safe to declare the encounter a dry bite, the person lucky, and let them go home.

Remember, all snakebites should be taken seriously and brought to immediate medical attention, but most will not require antivenin, and even those who do will tend to recover well.

Myth # 3: Suck Out the Poison

I love this one.  The idea is self-apparent: venom is in me, I want venom out of me, suck it out through the holes.  You’ve seen it in countless Old West movies, and it still pops up in modern entertainment, older medical literature, and even some out of date professional sites.  There are devices currently marketed to apply a constant negative pressure (~ 1 atmosphere) to the wound and actually do produce fluid, purportedly containing venom, that is then discarded.  As recently as the early 2000’s, these devices were advocated for short durations of time as they were felt to hold some potential benefit but pose little risk of harm.  Time and study has not been kind to this recommendation.

First the question of efficacy.  After needle injection of a radio-labeled fluid into volunteers, one study attempted to then remove it by suction using a popular commercially available pump; they successfully removed only 0.04% of the simulated venom.  In another randomized, controlled study pigs were randomized to receive suction therapy or no suction following injection of real venom.  The suction pump effected no improvement in symptoms in the pigs.  The bulk of the evidence, sparse as it is, indicates that these devices do not work.

Beyond being ineffective, suction devices also cause quite a bit of damage.  Even on normal skin negative pressure quickly forms a “hickey,” which is a bruising and edema of the skin.  Combine that trauma with skin being actively destroyed by the venom, and you simply generate a worse wound without reducing the venom load.  This is precisely what was found in the porcine study discussed earlier, and has been reported in the literature since. Significant harm + no benefit = bad idea.

Suction applied by mouth is even worse.  Not only does it just as ineffective while carrying the same risk as the devices (maybe a bit less, since the suction isn’t sustained), but now you add the oral bacterial flora of the human mouth to a fresh wound.  Snakes’ mouths are far from sterile, but bacterial infections after snakebites are uncommon enough (<3%) that antibiotics are not routinely prescribed, unlike human bite wounds.  Don’t compound the problem by giving the victim cellulitis.

If you are bitten by a snake and someone tries to suck out the poison, kindly go ask them to catch the snake instead.*

* Don’t do that.  Just tell them to call 911.

Myth # 4: Place a Tourniquet

In older survival manuals it was common advice to apply a tourniquet around the bitten limb, the thought being to limit the venom’s spread and to provide time to get to medical care.

There has been at least one animal study that demonstrated a longer survival time in pigs after envenomation with the use of a tourniquet (36 min longer), providing some plausibility to the benefit of tourniquets after snakebites.  However, the same study also showed markedly elevated pressure in the effected limb (43 mmHg higher) and led the authors to discourage the use of tourniquets for snakebites. But better to lose a limb and save a life, right?  Well, yes, if it were effective at saving lives in practice.

The trouble is that in practice tourniquets are fiendishly tricky to apply without causing further injury, and even with training under controlled circumstances professionals aren’t able to place them to the “proper” pressure.  Furthermore, clinical studies have failed to confirm the modest benefit seen in one animal model while demonstrating multiple serious complications from their use (tourniquets too easily become ligatures and compound the injury of the venom).

Tourniquets have their place in medicine, but it isn’t in the management of a venomous snakebite.

Myth # 5: Apply Ice

One of the hallmarks of a Crotalinae envenomation is swelling, pain, bruising, and often a burning sensation.  This superficially resembles other traumatic injuries, like a badly twisted ankle commonly treated with ice packs, so it makes some sense people are inclined to try cooling a snakebite.

Though there is a degree of hyperemia (increased blood flow) with envenomations that ice will reduce, the swelling is due more to the direct tissue injury of the venom. That direct injury also causes increasing pressure, clotting, and vascular damage all of which impede and at times stop blood flow to the tissue.  Anything done that further reduces blood flow (like ice or tourniquets) can make such injuries much worse.  Animal modeling has failed to show a benefit from cooling of the injury, and clinical studies have suggested that people may have more complications if their bites are iced.

There is, of course, also the more obvious risk of ice, in that it tends to be rather cold, and can cause injury to even healthy tissue if not closely monitored.  Yet again, we have little hope of benefit with clear risk of harm.  No ice.

Myth # 6: Taze Me, Bro! (Electrotherapy)

In 1986 the Lancet published the first paper in the medical literature where Dr. Guderian advocated high voltage electric shock of the envenomated site as a first aid technique. Subsequent studies in both animals and humans failed to show any benefit, and there has not been any significant presence of this intervention in the medical literature since 2001, which was a paper condemning its use.

Of course, this hasn’t stopped people from adding insult to injury by tazing their buddies who were just struck by a rattlesnake.  Yes, really.  Let that image sink in for a moment… there you go.  Dr. Guderian, or someone posing as him, puts forth the argument for electrotherapy of envenomations here.  As this is already a lengthy post, I’ll address this gem of a site and its specific claims at a later time.  Suffice it to say that beyond a very crude form of pain control, electrotherapy holds no plausible benefit, has significant risk of harm (like electrocution and burns), and has the existing literature stacked firmly against it.

If you are bitten by a snake and someone tries to taze you, kindly go ask them to go catch and taze the snake instead.*

* Again, don’t do that.  Just tell them to call 911, then re-assess your choice of friends.

What You Should Do

Odds are that neither you nor anyone you know will ever be bitten by a snake.  However, if you happen to find yourself joining those unlucky few, the best things you can do are incredibly simple:

1)    Calm the victim and calm yourself.

2)    Call 911.

3)    Immobilize the limb like you would a fracture and await medical assistance.

4)    Report any symptoms, no matter how odd or minor, to medical providers immediately as they occur.

What if you are days out in the wilderness, is it worth trying these interventions in a desperate situation?  No.  Being away from help doesn’t make useless and harmful interventions any less useless or harmful.  Instead, be responsible and have an evacuation plan for any medical emergency, including snakebites.  Now go enjoy the Spring!

Posted in: Science and Medicine

Leave a Comment (49) ↓

49 thoughts on “Snake oil for snakebites (and other bad ideas)

  1. Versus says:

    What? No homeopathic remedy for snake bite? No food supplements? No energy healing? How about “detoxification?” CAM practitioners are curiously silent when there is a real emergency to be addressed.

    Very helpful article — sent it to my children.

  2. Joel says:

    For those of us in regions with a more exciting variety of snakes, I assume it’s still worthwhile making an effort at identification (as long as you can do so with little risk)? Of course, those of us in the aforementioned regions are not currently in Spring.

    Is getting the limb below the heart likely to be any use? That does seem to come up a lot.

  3. versus on Science-Based-You’re-Not-Helping-Please-Don’t-Do-That:
    “What? No homeopathic remedy for snake bite? No food supplements? No energy healing? How about “detoxification?” CAM practitioners are curiously silent when there is a real emergency to be addressed.”

    Natural News says,

    Take homeopathic Echinacea (homeopathy):
    http://www.naturalnews.com/022392.html

    Eat a lemon (food supplements):
    http://www.herbreference.com/Modern_herbal-2.html

    Use a stun gun (energy healing):
    http://www.naturalnews.com/022386_electromedicine_electrical_stimulation.html

    Apply a Tibetan herbal remedy (detoxification):
    http://www.naturalnews.com/027117_chamomile_schisandra_disease.html

    … yep, check, check, check and check. One might wish they were more silent when it comes to real emergencies.

  4. Tantalus Prime says:

    I had been wondering about the veracity of these remedies recently (the ones I had heard of at least). Thanks for summing them up, as I kept forgetting to check snopes for answers. Very helpful.

  5. Jojo says:

    This is great information to know. I hope I never need to use it, but it will certainly help me to stay calm if it does.

  6. Michelle B says:

    No better way to learn important information than reading a well written and funny article. Thanks so much.

    (And post here more often, please)

  7. DevoutCatalyst says:

    @ Versus
    “CAM practitioners are curiously silent when there is a real emergency to be addressed.”

    We had Homeopaths Without Borders rushing to Haiti, and there are acupuncturists without scruples on our battlefields, both offering emergency services; a maverick chiropractor recommends vitamin C against rabies, etc. The curious silence you mention is not for lack of fanciful thinking. Give them time!

  8. DVMKurmes says:

    Some quacks are also recommending large doses of vitamin C, sometimes injected IM, which can cause tissue damage due to acidity, for snake bites. Some people are using it to treat animals in an attempt to avoid the expense of antivenin. I suspect the frequency of dry or mild bites convinces people that various forms of “first aid” work better than they actually do.

    http://skeptivet.blogspot.com/2010/04/snakebite-fact-and-fiction.html

  9. Harriet Hall says:

    There is a disturbing video clip about alternative snake bite treatment from the film “Guru Busters” at http://www.youtube.com/watch?v=T2_UQKEXI-s

    In a demonstration before a huge crowd in India, a dog is deliberately given a cobra bite and a “healer” treats him and the dog dies. The “healer” had been confident he could save the dog with the same treatment he uses on humans: he stood to win a cash prize if the dog lived. After his failure, he publicly admits (as required by prior agreement) that he had believed in magic and ritual but he was wrong. The rationalist who set up the demonstration has the crowd observe a minute of silence for the dog, whose death may have helped prevent many human deaths.

    There is no followup. I suspect that the “healer” simply moved to another location and is still offering his snakebite cure. But at least the people who viewed the demonstration were “immunized” against his kind of healing.

    On a lighter note, what does a snake say after he bites you? “Fang you very much.”
    (sorry!)

  10. Since it’s oddly relevant, I can’t resist sharing a very old hill song that my mom used to sing to us.*

    On Springfield mountain there did dwell
    A lovely youth I knowed him well
    Monday morning he did go
    Down to the meadow for to mow

    He scarcely mowed quite half the field
    When a pesky sarpent done bit his heel
    He took his scythe and with a blow
    He laid that pesky sarpent low

    He took the sarpent in his hand
    And straight away to Molly Bland
    Molly, Molly here you see
    The pesky sarpent would bit me

    Now Molly had a ruby lip
    With which the poison she did sip
    Molly had a rotten tooth
    And so that poison killed them both

    Yup he killed the snake so he could show it to his girl friend, she sucked out the poison and they BOTH died. Luckily they didn’t have a tazer.

    Thanks for the info Dr. A. You never know what’s going to happen so it’s good to be better informed.

    *My mother would insist that I inform everyone that she sang us plenty of “nice” songs, but we only liked the morbid ones.

  11. Versus says:

    Many thanks to those of you who pointed out that CAM practitioners are more delusional than I gave them credit for. I won’t underestimate them again.

  12. art malernee dvm says:

    once you start giving antivenin is there any data to decide if it needs repeated and if so how often?

  13. Peter Lipson says:

    Interesting. We have very few envenomations in MI, but one of my students was telling me about a boat trip she took with friends in TN a couple of years ago. One of her friends felt something hit him in the water, climbed out and they saw marks. When it became swollen and painful, they took him to the local clinic, who gave him antibiotics and motrin. The next day they found the snake on the boat and tried to get him more care in BFE but had to come back home.

    Apparently, his recovery sans antivenin took many, many months.

  14. I met my beloved when he came to Canada on a scouting trip looking for places to emigrate to. Australia didn’t make his short list because it has too many poisonous animals. He’s outdoorsy, and worried that not having grown up with the local fauna would not know how to be smart and would put himself in danger.

    So, he settled on mostly-poisonous-animal-free Canada instead (and changed my life).

    (À propos of absolutely nothing at all. Just thought I’d share.)

  15. lizditz says:

    Thanks so much, Dr. A., for this article. I’ve sent it on to several friends.

    I hike and ride my horse in the San Mateo county foothills (crotalus oreganus oreganus habitat). In all the years out of doors, I’ve only had one scary / close encounter, when riding my horse along an old ranch road, bordered on one side with a high, rocky cut, on which a snake was sunning. The snake didn’t rattle, but struck silently. I didn’t see it until it struck. Fortunately, the snake hit my boot, not my flesh, and left about a 3 inch mark on the boot — two parallel lines. We were able to make a positive identification, as the snake fell to the road, coiled, and began rattling.

  16. LovleAnjel says:

    What an informative article, thanks! I had always wondered about the efficacy of the snakebite suction kits.

    As for tracking down and killing offending serpents, I think there is far more to it than people thinking they need it for identification. It’s probably a mixture of prevention (so the snake doesn’t bite anyone else) and vengefulness (you bit my spouse/child/friend, so I kill you). People also feel the need to DO something while waiting for help– a better suggestion might be to tell people to photograph the snake (cameraphones being ubiquitous), which keeps them from close contact with the snake but makes them feel better.

  17. Todd W. says:

    Very nice article, Dr. Albeitz. In particular, it was interesting to read the bit about sucking the bite. As you mentioned, it is so ingrained in our popular culture. How many people attempt that? And how many more attempt it on a dry bite and conclude that it therefore must work?

  18. James Fox says:

    Thanks for the article. I do a lot of summer hiking where rattle snakes are fairly common so updated current information is always helpful good to have!

    Myth #3 led to a great Woody Allen memory, thanks!
    “… I’ve been bitten by a snake…!!”

  19. Alison “So, he settled on mostly-poisonous-animal-free Canada instead (and changed my life).”

    exchanged the risk of snakebite for frostbite :)

  20. lizditz says:

    I have a question about snakebites, specifically the victim profile and alcohol intoxication which I haven’t been able to verify through PubMed. Here’s what I have found:

    From Canada:

    According to Lorraine Vankoughnett, aka the “registered snake nurse” (she’s actually the patient care supervisor) at Parry Sound District Health Centre, David fit a typical victim profile. “Forty percent tend to be males in their late teens to early twenties and have alcohol on board. They’ve had a few drinks and tried to handle the snake.” Vankoughnett ought to know. Parry Sound District was home to half of all massasauga bites that occured in the wild in Ontario from 1971 to 1998.

    From a 2005 Los Angeles Times article, quoting Dr. Robert Norris, chief of emergency medicine at Stanford University Medical Center.

    His formula for the classic bite victim: testosterone plus tequila, T-shirts and tattoos.

    So — are young adult males more likely to be bitten, and is alcohol intoxication really that common in snake bite?

  21. weing says:

    “Myth #3 led to a great Woody Allen memory, thanks!
    “… I’ve been bitten by a snake…!!””

    Bananas

  22. What great information! I hike often in the summer with the Little Anthropologists in tow. We’re often (but not always) above the elevation where snakes are common. I’m definitely going to pass this along.

    Thanks!

  23. wales says:

    Very informative. I’d love to see a similar post on poisonous spider bites. I live in an area with black widows, brown widows and brown recluse spiders.

  24. wales says:

    Especially pertaining to pediatric spider bites.

  25. grendel says:

    In 1895 Australian poet Banjo Paterson penned “Johnson’s Antidote” which has to be one of the most entertaining snake oil snakebite poems. A brief excerpt:

    “Both the dogs were duly loaded with the poison-gland’s contents;
    Johnson gave his dog the mixture, then sat down to wait events.
    “Mark,” he said, “in twenty minutes Stump’ll be a-rushing round,
    While the other wretched creature lies a corpse upon the ground.”

    But, alas for William Johnson! ere they’d watched a half-hour’s spell, Stumpy was as dead as mutton, t’other dog was live and well. And the scientific person hurried off with utmost speed,
    Tested Johnson’s drug and found it was a deadly poison-weed;
    Half a tumbler killed an Emu, half a spoonful killed a goat,
    All the snakes on earth were harmless to that awful antidote.”

  26. pmoran says:

    What about bandaging the limb to (supposedly) reduce lymphatic flow? This has been standard advice in Australia for some time — e.g.

    http://www.anaes.med.usyd.edu.au/venom/snakebite.html

  27. grendel says:

    Bandaging with a pressure bandage serves to immobilize the limb – and provides some pressure to reduce lymphatic flow. The Australian Venom Research Unit at the University of Melbourne maintains an up-to-date treatment list for all venomous species – including one most people never have to deal with, the Platypus.

    http://www.avru.org/

  28. Platypus? Jez, you Australian are a tough crowd. Even your cute furry cartoon creatures are venomous.

    signed – micheleinmichigan, who has a pack of male mallard ducks roosting on her roof and is really glad they’re not poisonous.

  29. BillyJoe says:

    Hey, what’s this antivenin $#!+

    It’s ANTIVENOM!

    Goddamn american french canadians.

  30. JMB says:

    @litzditz

    “So — are young adult males more likely to be bitten, and is alcohol intoxication really that common in snake bite?”

    I think that’s a sampling bias that is correlated with the location of the Emergency Room.

    Metro ER: Increased incidence of drunk macho snake handlers

    National Park proximity ER: Family member who decided to sit on that rock or log off the beaten path

    Rural ER: Somebody who was clearing dead brush, moving rocks, or hunting

    @pmoran

    I thought a basic principle was slowing lymphatic flow as well, provided it did not significantly increase the time to reach the ER. Slowing lymphatic flow can be as simple as making sure the extremity is kept at a lower level relative to the heart. Don’t raise the leg because it is swelling.

  31. cloudskimmer says:

    Thanks for the great post. I lead nature hikes at a National Trust property, and love to correct misinformation people have, which often causes them to fear the natural world.

    One thing I tell them is that you practically have to step on the snake in order for them to bite you. I have also heard, but have no source, that women tend to bitten on feet, legs and ankles, while men tend to be bitten on the hand and arm… and you know what that means: men are more prone to pick up snakes.

    I also heard a segment on National Public Radio (probably by Michael Ellis–this was a long time ago) that there are four things you can do to avoid getting bitten by a rattlesnake: 1. Don’t be between the ages of 18 and 25. 2. Don’t be male. 3. Don’t be drunk. 4. Don’t pick up the snake! Again, no evidence, but it serves as a funny anecdote to discourage people from picking up, playing with, or harming snakes.

    I certainly plan to pass on the great information in this post — especially about NOT killing the snake. In my case, I want the snakes to be left alone, but I’m happy that this protects people, too. The risk of driving to a park is probably much higher than anything that could happen on the trail.

    BillyJoe: I’ve seen “antivenom” but it isn’t a word in my dictionary. The correct term is indeed, antivenin. The Latin “venenum,” from which it is derived (blame the Romans, not the French or Canadians) means poison, and love-potion! The “-in” comes from chemical and mineralogical nomenclature, and is, again, from the Latin. That is from the Random House College Dictionary revised edition, 1975, selected because it’s on my shelf.

  32. DVMKurmes says:

    @ artmalernee;

    there is not really any standard dose of antivenin because there is not a standard snake envenomation. It depends on the size and species of snake, and how much venom the snake decides to inject. The dose is adjusted based on the severity of signs, the initial response, etc. That type of variation probably makes it difficult to generate reliable data that would apply in a general sense, and difficult (and unethical?) to run a controlled trial on bite victims.
    There are some rodent experiments demonstrating how much venom a standard dose of antivenin will neutralize, but obviously no way to know exactly how much venom was injected in a real world bite.

  33. BillyJoe says:

    cloudskimmer

    “BillyJoe: I’ve seen “antivenom” but it isn’t a word in my dictionary. The correct term is indeed, antivenin. The Latin “venenum,” from which it is derived (blame the Romans, not the French or Canadians) means poison, and love-potion! “

    It isn’t in dictionarydotcom either!
    Unbelievable!

    Actually, it is the word used here in Australia (and, therefore, I suppose England, because they always do exactly as we do!). The other word used occasionally is antivenene.

    The word “antivenin” is derived more directly from the french word for venom, which is “venin”. Hence the american canadian french reference I made.

    Most importantly and authoritatively, the WHO officially adopted the word antivenom way back in 1981. So catch up all you frenchman, canadians and americans. And update your friggin’ dictionaries.

  34. laproxdoc says:

    @artmalernee –

    DVMKurmes is quite right: from a practical standpoint we titrate the antivenin dose to the effects of the snakebite. Rattlesnake venom is primarily a cocktail to begin the digestion of prey as well as prevent the victim from getting too far from the snake before it dies, and also contains chemical scents emitted from the lungs of the prey to allow the snake to find its dinner whichever way the victim may try to scurry away. It is the result of a long successful evolution. Unfortunately evolution marches on, the snakes here in San Diego county are getting more aggressive and the venom more toxic in recent years probably due to reduction of food and habitat availability because of increased urbanization. Oh, yeah, in urban San Diego we see bites on the legs and ankles of morning joggers who step on snakes warming themselves camouflaged in the sunny leaf litter on our trails as well as the hands of seniors who reach without looking under their RV’s thinking the rattling is the hissing of an air or water leak.

  35. wales says:

    according to webster’s dictionary antivenom is a noun dating to 1904

  36. squirrelelite says:

    @wales,

    Just FWIW, I got curious because of your 1904 reference, so I dug out my compact OED. The supplement section has antivenene with an 1895(?) reference from a “Pharmaceutical Journal” about “observations of antivenene and the production of immunity against serpents’ venom”.

    The 1902 edition of the Encyclopedia Britannica states that “the serum is found to act as an antivenin”.

    And, a 1912 reference states that “by the repeated injection of minute quantities of venom into lower animals, anti-toxins or antivenins can be obtained for all the animal poisons.”

    Since Webster’s is mainly an American dictionary, antivenom was apparently being used in North America while the Brits were still referring to antivenene or antivenin.

    And, just above it in the supplement is anti-vaccinist!
    I think it has an 1822 reference, but those old fonts are hard enough to read even before they are shrunk down to microscopic size.

  37. wales says:

    Interesting. Those early Americans tried to distinguish themselves from the Brits in many ways. I’ve always wondered about why we drive on the right side of the road vs. left…..just trying to break away from the “chains that bind” I guess.

  38. cloudskimmer – “that there are four things you can do to avoid getting bitten by a rattlesnake: 1. Don’t be between the ages of 18 and 25. 2. Don’t be male. 3. Don’t be drunk. 4. Don’t pick up the snake! Again, no evidence, but it serves as a funny anecdote to discourage people from picking up, playing with, or harming snakes.”

    Years ago in a national park presentation for backpackers I was told that rattlesnakes like to curl up at the base of logs or sun themselves on the paths. One way that hikers get bit is by stepping over logs within checking the other side of the log. Better to step on top, look, then step down. The basic rule was ‘don’t put your hands or feet were you can’t see them. This was also a rule that I was taught in working with power tools. so it’s has a nice multipurpose rule.

  39. stepping over logs withOUT checking, that is.

  40. grendel says:

    Micheleinmichigan – does the presence of the Mallards mean that you live life under quacks?

  41. gendel – Mallards may not be onto SBM yet, but they are very efficient.

    They don’t let anything fall through the quacks.

    so very sorry for that. ;)

  42. grendel says:

    Oh I consider it my own fault for ducking into this fowl territory of avian puns in the first place. I quail with fear about what may follow.

  43. TsuDhoNimh says:

    @lizditz … The characteristics of the rattlesnake bite victims we got in a Phoenix AZ trauma center: Overwhelmingly male, blood alcohol well into the DUI range, and 16-24 years old. Typically they had been doing something really dumb with the snake after imbibing too much booze out in the desert.

    1 – Tried to KISS the snake.
    2 – Tried to show off his fast ninja reflexes and grab the snake in mid-strike.
    3 – Picked up a rattlesnake behind the head and was chasing his girlfriend with it.
    4 – Showing off with the snake, dropped snake in his lap.
    etc.

    There were a few true accidents, like the woman who got a flat tire, pulled to the side of the road and stepped on the snake she had just run over.

    Recent victims from the papers include the guy who was walking with his (apparently) unleashed dog. Dog went into a bush after the snake and the guy got bit trying to grab the dog and pull it away from the snake. Had it been leashed, there would have been no problem.

  44. art malernee dvm says:

    Some veterinarians repeat antivenin so I just assumed human doctors did. Thats why i ask for data about when to repeat it. My bad.

  45. TsuDhoNimh says:

    Art – Antivenom would be repeated in humans if the symptoms didn’t improve. Criteria like reduced swelling and less pain means it’s working, but it’s not a predictable thing.

    There are so many variables: size of snake doesn’t correlate with amount injected, site of injection may sequester venom, patient susceptibility varies. They aren’t easy to treat when they are bad.

  46. art malernee dvm says:

    Art – Antivenom would be repeated in humans if the symptoms didn’t improve.>>>

    how often? I have read veterinarians saying they give antivenom every hour if symptoms do not improve or until the owner runs out of money for antivenom.

  47. DVMKurmes says:

    @ art malernnee;

    Cost is certainly a factor for pet owners when treating with antivenom. I have heard of some severe cases of human envenomation where literally dozens of vials needed to be used. That can become cost prohibitive when treating an animal, an I would be surprised if many small veterinary clinics had that much antivenom in stock. As TsuDhoNimh said, severe cases are difficult to treat. On the other hand, many bites are relatively mild, and sometimes only one or two vials of antivenom do the job.

  48. grendel on 16 May 2010 at 8:59 pm

    “Oh I consider it my own fault for ducking into this fowl territory of avian puns in the first place. I quail with fear about what may follow.”

    I have no egrets.

  49. Calli Arcale says:

    Things can get downright loony, though. I mean, take a gander through the archives; you’ll find plenty to crow about.

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