Effects of Venom on the Heart

[David_F]

" i couldnt see or think clearly then i began to have difficulties swallowing, i forgot where i was and was sweating an extremely nautious .."
--->http://www.arachnoboards.com/ab/showthread.php?t=939

This happened to me the first time I rehoused my first P. murinus. I didn't get bitten though. So, should I just assume they have the power to kill me by looking at me? I guess so. Anybody want to buy a collection of Ts? I can't keep these dangerous things around any more.

 

[Crotalus]

I think I sad what I wanted to say on this thread so I leave it now. But, again:

Should we talk about tarantulas and tarantula venom as dangerous? I dont think so. I prefer to stick with facts and not fiction.

/Lelle

 

[bagheera]

So going from the facts and bite reports, it is clear that anyone with cardiac issues would certainly NOT enjoy a bite from one of the more potent varieties of T's. It is likely envenomation from one such animal would cause the patient more discomfort and a longer time to recuperate than if they did not have cardiac issues. Just be careful.

I have met many vampires in my life. In this modern world, they have adapted to remain undetected--they take the form of mosquitos, ticks and fleas.
(Nosfertus mosquitos)

 

[Sean]

I dont think anyone should refere to a T is a dangerous animal. But there is always a "chance" that maybe it could cause a death. Im a sever asthmatic. A bee sting could kill me. A wasp sting could kill me. Im severly allergic to dust/grass/mold. If those things could send me into the ER. Who knows what a T with more potent venom could do. I work in the hospital and see people in the cardiac unit all the time who have diffrent things wrong with there heart bradycardia/tachycardia who knows what a bite from a "Potent" T could do to a person like that. I like to think just because it hasnt been reported dosent mean it cant happen. But im not one to spread false info. When people see my collection and they say "those can kill you right???" I just say, "no death has ever been reported from a T bite" I leave it at that. But you always have to kinda think someone "could have an allergic reaction".

I mean think about it. If someone has an allergic reaction to something like "peanut butter" or "Onions" couldnt there be a possibility that if the wrong person was bit by one of these creaturs they could have an allergic reaction and die??

 

[Crotalus]

sean, spider venom isnt allergenic.
Why you ask? Use the search function I answer.
Def. the last post here from me.

/Lelle

 

[Sheri]

I mean think about it. If someone has an allergic reaction to something like "peanut butter" or "Onions" couldnt there be a possibility that if the wrong person was bit by one of these creaturs they could have an allergic reaction and die??

This is not useful as a measure of venom strength. Is penut butter venomous? Onions? No. Allergic reactions and medically significant venom are two different things.
And I think Lelle has some data somewhere that explains why people do not react through allergy in the same manner to T bites as they do to bee stings.

 

[becca81]

And I think Lelle has some data somewhere that explains why people do not react through allergy in the same manner to T bites as they do to bee stings.

I remember Lelle providing some info somewhere on this, but I can't find the thread.

I thought, though, that it wasn't a certainty, just a conjecture.

 

[danread]

I haven't read the paper, but another paper i have references this paper as an example explaining why spider bites don't cause allergic reactions:

Isbister, G. K., and Gray M. R. (2002) A prospective study of 750 definite spider bites, with expert spider identification. QJM. 95 (11): 723-731

 

[Venom]

"We know of other dangerous spiders. Leave snakes out of it entirely. Think of true spiders in remote places that are known to be dangerous. Why would we know of those species that cause death or serious injury but not tarantulas."

Because no one expects there to be any deaths from T's. None of the field scientists at least. T's are not among the most potent arachnids, so they are assumed to be always nonlethal. Think about it, we know that true spiders have caused deaths, we know that Hexathelidae have caused deaths. We have tested their venoms and found them to be very potent in some species, so we look for deaths from the medically significant species in these groups. T's have not been found to have dangerously low LD50's, and haven't yet been reported to have caused deaths ( reasons for this discussed in earlier posts ) so, the scientists don't inquire about deaths from T's. The lack of interest, and admittedly, the rarity of such deaths I think could be a reason why we don't hear of T caused deaths.



"Wanting to think something cannot replace logic, science, or evidence. I would ask why you want to persist in this notion despite the lack of any evidence or research that suggests it might be true?"

Because I really do think there is enough evidence to suggest that a T could cause a death in an unhealthy person. As Sean said, what about the people with severe ailments of the heart? What about feeble children in third world countries? Obviously, I don't have any direct evidence to show that a T death has happened. I am using the bite reports that we have from the comparatively much healthier hobbyists, which involved some rather serious symptoms, and, putting that together with what I know of medical conditions which affect the same organs which some of these T's seem to disturb ( breathing, heart rate ), I am coming to the logical conclusion that the effects of the very strongest T venoms added to the effects of some very serious medical impairments, might be enough to push a person over the top, as they say. Is that so unreasonable?

I think I have stated my case for this possibility very clearly now, for people who have an open mind.

"One of the truly remarkable things about our hobby is that we can keep these remarkable creatures without much risk, and we have the opportunity to educate rather than perpetrate an unfounded fear."

Yes, that fear is unfounded for 90+% of tarantula species, and the rest aren't "deadly" either. New World species don't even figure in here. Some Old World species, however, I think we should take a little more seriously.

edit: Perhaps it would be a good idea to have a poll on this topic, to see what people here think on this issue.

Lol, I hope you got something of an answer out of this, Becca.

 

[Sheri]

edit: Perhaps it would be a good idea to have a poll on this topic, to see what people here think on this issue.

Done.

 

[Crotalus]

Yes a poll here would definitly settle this once and for all..... Come on Venom, are you seroius?? The lack of interest of t deaths is why we donmt here about them? Again, the reason why we dont hear about them is because it dont exist. There was one species from South Africa, Harpactirella lightfooti, that was supoosedly dangerous to humans - so they sad - and this information was in almost every older book about tarantulas. However, its been all a bad case of misinformation. No scientific tests have shown this species to be any more potent then a average african tarantula.

Ok. NOW its enough

/Lelle

 

[Venom]

"Ok. NOW its enough"

Agreed. I've had enough for now.

 

[becca81]

No scientific tests have shown this species to be any more potent then a average african tarantula.

Do you consider the potency of an "average african tarantula" to be any different than the potency of an "average mexican tarantula?"

 

[Crotalus]

Do you consider the potency of an "average african tarantula" to be any different than the potency of an "average mexican tarantula?"

By average I mean some pain, cramps and swelling. Im sure there are NW species causing the same effects. I wrote "average african tarantula" because it was a african species, once believed to be deadly.

/Lelle

 

[danread]

I'm inclined to agree that there is the potential for death in some unfortunate circumstances. It's a similar situation with Scolopendrid centipedes. There has never been a recorded death due to a bite from a pet centipede, which would make you assume that there is no potential for a life threatening bite from these animals. But there have been two recorded deaths from Scolopendra bites in their natural range, not many considereing how common they are in some parts of the world, but it goes to show that it can happen.

 

[Crotalus]

I'm inclined to agree that there is the potential for death in some unfortunate circumstances. It's a similar situation with Scolopendrid centipedes. There has never been a recorded death due to a bite from a pet centipede, which would make you assume that there is no potential for a life threatening bite from these animals. But there have been two recorded deaths from Scolopendra bites in their natural range, not many considereing how common they are in some parts of the world, but it goes to show that it can happen.

Im not so sure I would make a comparison between theraphosid venom and scolopendra venom. There might be some differencies that makes scolopendra venom more dangerous.
I know one person here that got bitten by a scolopendra ssp. and he was feeling the bite for weeks.

/Lelle

 

[Dephiax]

Well, it's a little bit offtopic, though I got kinda like the same question...

I read in this topic T's aren't cardiotoxic, though my dad has some kind of illness to his lungs. Sometimes he has problems with breathing, will a T give ANY problems (not only the venom, but maybe the hairs or something)?

 

[arachnoguy]

everyone seems to have the right set of ideas. i don't think it is the venom that directly effects people but more your bodies reaction to it. another key point is your health. if you have a weak heart and you get bit by a tarantula then more than likely the rush of adreneline will be more likely to kill you than the venom. i have diabetes and i have been bitten by some pretty nasty species and the worst that has ever happened to me is a bit of swelling, cramps and nausea. also whos to say that people haven't been bitten and their death is reported as something else. i think it all boils down to everyones personal health and physiology.

 

[xanadu1015]

Could allergic reactions from tarantula venom cause heart problems several hours after a bite or would the body have already metabolized the venom by then? Let me clarify, my mom was bitten by her mature male OBT (he had his mature moult last week) after he escaped and she tried to catch him. Her system seem handle the venom very well. There was only localized swelling and that was minimal and she had some pain and stinging. This morning she has some muscle aches and chest cramps. Her heart takes extra beats/skips that sort of thing (I forget the name of this condition), so now I'm wondering if there are going to be any problems that I need to worry about. Please, correct me if I am wrong.

 

[blacktara]

Ok, this is not a simple topic, but here are some thoughts

One, a venom can have an effect on the heart through a neurotoxin effect. If it affects nerves that innervate the heart, then it can affect the heart, increase heart rate for example (tachycardia)

Seperate from this is the possibility of a direct toxic effect on heart muscle. This weakens the heart, resulting in what's called a cardiomyopathy (cardio - heart myo-muscle path-disease - a sick and therefore poorly functioning heart muscle) It can cause a previously healthy heart to be weak, and can further weaken an already weak heart

Now, how could this lead to death? One, it could weaken a heart to the point where it fails - yields severe heart failure to the point of circularoy collapse

Two - ALL of the effects of venom, neurotoxic, lytic, cardiotoxic, release of adrenaline from fear, ALL of it represents a physiologic stress. A healthy heart can handle a physiologic stress much better than a weak heart. At some point, the weak system may not be able to handle the physiologic stress, and the system collapses - you die. Thus, the weak and frail can die from the physiologic stress of an evenomation that may be merely a painful unpleasant experience from which a healthy adult recovers

Now, I have NO CLUE as to which T's have specific direct cardiac toxicity. The species whose bites produce more serious effects as a rule (Pokies, Usumbara) are obviously producing more physiologic stress. You figure it out

My advice? Dont get bitten - If you have any doubts on how dangerous a species might be to you with your particular condition, err on the side of safety

As I hope you can see, it's not so simple as a yes/no question and answer

Now, about T venom in general. No reports ever of a confirmed fatality from a T bite in a healthy adult. That should say something - but can we say for sure that this is because it doesnt exist? NO- new species are discovered all the time. Would it be UNUSUAL that suddenly some new species or subspecies of T is found whose venom is vastly more toxic to humans than any other known so far? Yes, but not unprecedented. For example, there's lots of therdeids, but only Latrodectus species are significantly venomous to humans (of course, it's been known about since forever). But what's out there in the jungles? Lord knows - but blanket statements that we KNOW something that we simply cant know for sure can be dangerous