Re: Maybe someone in here can answer my question....

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Posted by WK on December 03, 2002 at 10:22:50:

In Reply to: Re: Maybe someone in here can answer my question.... posted by tommyboy on December 02, 2002 at 18:21:48:

Making sense of all the venom numbers and how they relate to clinical effects is very difficult and, in my opinion, a waste of time. Most venomous herp enthusiasts are primarily interested in the effects of envenomation on the human body because they want to know what might happen in the event of a bite. Venom researchers produce many data on venoms and their various components. It is understandable why venomous herpers try to make connections between these data and the clinical potential of envenomations, but physicians who treat snakebite envenomations almost never think about LD50, venom yields, scores on hemorrhagic / hemolytic / proteolytic tests, etc. Can you imagine a paramedic busting through double doors of an emergency room, pushing a stretcher holding a guy who just tried to kiss a rattler, [paramedic] shouting out as he goes, �I�ve got a canebrake bite to the nose here! Mouse intramuscular LD50 is 2.0, venom yield approximately 125 mg! Omori-Satoh hemorrhagic activity score four-point-two-three-ohh-ohh-ohh-oh-ohhhhhh!...�? LOL! You won�t ever see this (unless it�s on the TV show ER, or perhaps if the paramedic is CH) because all that stuff does not influence treatment and, therefore, is largely ignored by medical workers.

If you really want to see what happens when a C. molossus bites a human, look for case reports describing what happened when a C. molossus bit a human. A good place to do this is the free search engine, PubMed, located at www.ncbi.nlm.nih.gov/entrez. Type in your species of interest (use the Latin) and you�ll get back case reports, if there are any, describing what happened. Doing this for C. molossus brings up only one case report describing two northern blacktail bites. First one involved a 31 year old male bitten while pointing a finger at 4.5 ft blacktail rattlesnake. He presented to the ER 30 minutes following the bite with a swollen hand. The patient appeared �comfortable�, so he initially received a tetanus shot only. By 2 hours following the bite, his entire forearm was swollen. Blood coagulation studies were abnormal (blood not clotting as it should) and his platelet count was low (platelets = one of the formed elements of blood that are key in forming clots). At this point they start giving him Wyeth ACP for a total of 30 vials over twenty hours. By 16 hours, his arm was swollen to the armpit / shoulder, with blistering of the finger and bruising involving one side of his entire arm. Things got better after this, with the swelling essentially gone by six days. He never developed internal bleeding (which is the main concern when clotting times are up and / or platelets are low). Next case involved a 42 yr old male �seized� on the wrist while free handling his large (text says 7 foot!!) pet blacktail rattler at home. Essentially, the same thing happened to this guy with the exception of more severe swelling / bruising / blistering (swelling involved whole right arm and entire left upper body), but, interestingly, no clotting abnormalities. This genius earned 21 vials of WACP. He was still having trouble with grip strength and wrist mobility 2 yrs after the bite.

There may be more case reports out there that someone here can tell you about, but you get some idea of the potential of C. molossus envenomation from these two incidents. I did not see any mention of documented fatalities from this snake, but I don�t doubt that it can kill you. For comparison, there are numerous reports of fatalities from both of the big diamondbacks.

I don�t know the LD50 for C. m. molossus, but the southern subspecies� (C. m. nigrescens) intraperitoneal mouse LD50 is reported as 2.35. I�m not up to date on my rattlesnake systematics so nigrescens may no longer be valid. Anyhow, I would think this LD50 value is comparable to that of the northern blacktail rattlesnake. Russell reports i.p. LD50s of C. atrox and C. adamanteus as 3.71 and 1.90, respectively.

Sorry for the long response, but you said the magic words � �I am learning as I go and appreciate the help.� More often than not, this will prompt a reply from me.

Cheers and Happy Holidays (may your stockings be stuffed with wriggly, scaly treats),
WK

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Thank you.... tommyboy 12/03/02 (0)