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Has there be much research about the volume of venom snakes carry. Has anyone determined the "full load" of various hots. I have a southern copperhead and its LD50 is 25.6 mg/kg. Doing the math would require 1792 mg of its venom to kill me. What's the volume of an average bite? and then what's its full capacity?

This may be an inconsequential question. Sorry.

Regards,
Dimitri

First off, I'm far from an expert, but have some input. There are some venom charts out there that have maximum yields, but pretty much every one you see has different numbers. I think the average yield of a copperhead is between 20 and 30, with a max around 40, which is also the lethal dose. Don't quote me on this, this is only what I've compared from a number of different sources. Copperheads can just barely make the lethal dosage, and for a healthy adult, probably wouldn't happen. Be careful about venom charts, they can be misleading. You see bushmaster at 33 or 36 on most venom charts, making it seem like it is less toxic than copperheads. If someone where to get bit by one, they'd be in ALOT of trouble, it's one of the most misleading venoms in my opinion. Remember, most tests are done with rats, not humans. So it could effect a human differently than it could a rodent.

>>Has there be much research about the volume of venom snakes carry. Has anyone determined the "full load" of various hots. I have a southern copperhead and its LD50 is 25.6 mg/kg. Doing the math would require 1792 mg of its venom to kill me. What's the volume of an average bite? and then what's its full capacity?

That figure applies to lab mice. You are not a lab mouse. Different animals, of which we are one, can differ hugely in their susceptibility to many snake venoms, so you can't extrapolate from mouse LD50 data to how much it would take to kill a human. For that matter, even a different strain of lab mouse may show a distinctly different LD50, and if you collect a bunch of copperheads 20 miles away from the ones used to get the 25.6 mg/kg figure, then you may find them several times more or less lethal - and that's without even going into individual variation within a population, which can also raise or lower lethality severalfold.

Basically, LD50 figures are of use in some research, e.g., to test to what extent an antivenom neutralises a venom, but they don't mean %#@&* as far as assessing the danger to humans is concerned. Arguing about the decimal point in LD50 comparisons is thus the height of futility.

Cheers,

Wolfgang
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Hi mate

As has been already pointed out, LD50 charts are compiled using mice not humans and thus they may not translate directly across. However, the variance between humans and mice will most likely be quite a bit less than the variance between chickens and humans but in either case, common pathways are present so reasonable extrapolations can be made. For example, the blood coagulation cascade is the same and thus a prothrombin activating toxin will have the same mode of action in both. Similarly, the receptor targeted by colubrid/elapid neurotoxins is virtually identical between human/mice/chickens and therefore the relative toxicity will mostly be consistent between them (but not identical of course, with some venoms varying more than others between the models).

Therefore, while LD50s are not a precise guide, they are of tremendous use in providing a reasonable roadmap regarding potential human toxicity. There will certainly be a swing but it won't be dramatic enough to put an American copperhead before a taipan as an extreme example.

Cheers
B
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Dr. Bryan Grieg Fry
Deputy Director
Australian Venom Research Unit
University of Melbourne

www.venomdoc.com