Reptile & Amphibian Forums

How long will it take for a partially removed venom duct to regrow on a cobra?

Once the venom duct is entirely removed, is it possible for a cobra to ever have a wet bite?

What are the biological implications if any, on cobras that have their venom ducts removed?

Research for a school project. Thanks....

A school project eh...

Well, as for the biological implications of such a "removal" I must say that such surgery might not really be in the best interests of the snake's health. Outside of the initial and potentially ongoing pain associated with the removal of venom glands and ducts, the loss or reduction of venoms must have dietary implications due to their catalytic role in digestion alone.

The regenerative capacity of the structures and their products would also obviously influence toxicity, and I would caution that such toxins might actually become modified in the process and this could have unpredictable consequences should an envenomation later occur and require treatment. In other words and contrary to the usual belief, it does not necessarily follow that such surgery would make a venomous snake LESS dangerous.

At this point I readily admit that I am pretty much out of my depth here, and your questions would really be best answered by a physiologist experienced in such matters, but I can understand why you ask them. I am also asking those questions and others as a result of such activities here in Australia.

When I first heard about this "venomoid" business I immediately thought back to an infamous paper published in Australia back in 1963 where the venom glands of a Tiger Snake (Notechis scutatus) were "surgically" removed by the brilliant son, of a brilliant doctor. The brilliant son, however was not a doctor, but an amateur herpetologist of undoubted potential, but nevertheless not trained in physiology. Consequently, for over 40 years this paper has been periodically mentioned more for its perceived callousnesss than its originality. It could even be argued that it's ultimate effect actually sterilized the potential career of the herpetologist more effectively than it did the Notechis venom!

And this gets to the point of this current issue - what do we actually know about this activity?

In applying the 5 questions of good journalism to science we can really get to the guts of an issue - who, what, how, where and why. When one looks objectively at this "venomoid" business the little answers just leave big questions...and very serious questions at that.

So I must also confess that I am left more than a little cold at the "practice" as currently presented. From what I have observed in recent years, I must say that this attempt at detoxifying snakes by surgery is rather disturbing because it seems so amateurish and consequently so unnecessary.

In case some might want to consider using such information in a more practical sense than simply for a school project, I would hope you consider the following: Unless carried out by an appropriately trained veterinary surgical team, such operations run the risk of being little more than amateurish butchery. I believe that most untrained people who are involved in such surgical barbarity are dealing with physical and biological issues that are beyond their comprehension.

But even when undertaken professionally, one must ask...for what good purpose is this done? It would certainly not be without serious risks to the ultimate well-being of the snakes concerned.

Such surgical activities have recently been carried out here in Australia as well, and there have been justified calls for the reptile keeper responsible to be arrested on animal cruelty charges.

This particular individual here in Australia thinks playing doctor in a pretend surgery for chopping up snakes is science. Well, it is not. It is simply animal cruelty of the most base kind, hiding behind a transparant mask of pseudo-science, and practiced by the intellectually challenged.

Richard Wells

Good on ya Mate! Well said!

Cheers!

Al
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Save a Rattlesnake...Skin a Sweetwater Resident!

I enjoyed reading that and I think it should be used every time this question comes up. Well written and well said.

AMEN!! An intellectually stimulating response to a horrible practice. Well said and I hope the questioner will take this to heart and not support such cruel activity.
Cheers
Brett

Not taking sides in this matter of removing venom glands, I always have the same question when I hear the argument about the removal of the glands having "dietary implications". Is the health of the snake really jeaprodized?

The injection of venom into prey starts the digestion process which actually kills the prey. Indeed, the venom is digestive enzymes. I can see a benefit to this but not that important as non-venomous snakes have no problem with digestion. Also, pre-killed prey given to venomous snakes do not appear to cause any digestion problems, nor "dietary implications". Also, venomoid snakes seem to be living long healthy lives.

Can someone shed their feelings on this? I am not interested in the rights and wrongs of the issue, only the physiological digestive problems that can arise from gland removal. Thanks.

I hope a dietary physiologist is out there to help answer your question because it is definitely worth getting more on it.
And yes, I can see you point, but it seems to me that this is an inescapable conclusion to the facts at hand. As far as diet and venom action is concerned, the action of the venom components on the prey during immobilization seems to me to mainly prepare it for digestion. Neurotoxins are the shock-troops that block nerve signals to muscles, with the end result that not only is the prey’s mobility compromised, so too is its capacity to biochemically defend itself from other invading toxins. The proteolytic enzymes (proteases) digest proteins. Hyaluronidase depolymerises hyluronic acid resulting in the breakdown of the sticky gel between cells and so enhances the rapid breakdown of normal cellular tissue. Phospholypase attacks fatty acid residues and facilitates the breakdown of nerve tissue. The effect on the breakdown of blood through clotting or anti-clotting inclusions is well-known. Once the prey hits the stomach its just a mopping-up operation really.
As I’m sure you would know, venoms are mixtures that contain extremely complex biological compounds and the extent of this complexity is still unresolved. Similarly the variation and biological functions of such components are still not fully known. Venom structure may even vary among geographically separate populations of the same species, reflecting differences in prey type availability and/or the length of time of each population’s isolation. In some species there may be seasonal variation in venom toxicity (ie structure) and in others apparently not. Venom structure may even vary between males and females, and particularly ontogenetically. Despite this variation, the common thread is that diet and venom have co-evolved. So, venom plays a significant, if not the main, role in digestion of prey and this is a direct result of what is already known about the structure and function of venom itself. But there are other strange inclusions in snake venom that are almost totally unknown – such as retroviruses. What the hell is their function? The precautionary principle should be adopted in regards to the removal of venom glands just simply because we do not know for certain what the physiological consequences of such removals may have. Just the inclusion of specific retroviruses within snake toxins should be grounds for caution, because of their propensity for mutation when exposed to new conditions.

But just to finally comment on a few of your points….

“The injection of venom into prey starts the digestion process which actually kills the prey.”

Yes and no. Quite often prey is swallowed in an immobile or paralysed state, but it is still quite alive. If not before, death may occur soon after arrival in the stomach. Much of the action of venom on tissue depends upon the animal being alive for as long as the functional nature of the components allow. The need to promptly secure prey often results in the event of swallowing preceding the event of death.

“Indeed, the venom is digestive enzymes.”
Yes and no. Venoms per say are not just digestive enzymes, but I agree that many venom toxins are enzymes, although the majority are proteins.

“I can see a benefit to this but not that important as non-venomous snakes have no problem with digestion.”

So-called non-venomous snakes do in fact possess complex enzymatic secretions that are analogous to the venoms of other snake families, and these it would seem are primarily used in prey digestion. So yes they have no problems with digestion because their secretory systems are not being gouged out. This could in fact be a warning to be cautious about labelling some species as non-venomous simply because they lack conventional venom apparatus as Dr Fry has suggested.

“Also, pre-killed prey given to venomous snakes do not appear to cause any digestion problems, nor "dietary implications". “

Well that sure appears to be the case on the surface. However, I would suggest that all the balls are up in the air at the moment on the effects of diet on the well-being of an organism. You see, a big fat disease-free snake in a box doesn’t necessarily mean that its development has not been damaged by its diet. I mean to say, just take behaviour. The world’s classrooms are full of healthy looking kids that are just plain psychotic because of one sort of dietary problem or another – and I suspect that some of our collections have cages full of snakes that may be similarly exhibiting behavioural abnormalities that could easily be corrected by diet. We live with such change every day, but that doesn’t mean that it is inconsequential. Such diet-induced abnormalities may be reflected by changes in simple diel cycles or even in seasonal cycles of particular captives and this could easily have long-term reproductive consequences – I’ve lost count of the times that I have heard something like…“they look great, but why didn’t they breed this year?” To be sure, some dietary-induced behavioural changes may be very subtle and only discernable by the keenest eye – such as a more lethargic state or even a more active state that can’t be explained by the prevailing physical conditions. Many field Herps would also be familiar with how much quieter some species are in captivity when compared with their counterparts in the wild state and this difference in behaviour might in part be explained by changes to their diet. Although I am more familiar with field behaviour, I should say that I have kept a lot of snakes in captivity and in my opinion what they eat can affect how they act. I think snake diet has become just another symbol of the fast-food times that we live in. Snakes that are lizard-eaters are quickly converted to mammal-eaters more through the imperatives of human convenience than through the natural needs of the snake. That’s my opinion – I just like it as natural as possible. Whether this is good or bad would lead to thousands of opinions one way or the other I am sure. I won’t bother with the potential long-term problems of abnormal diet such as those that may be reflected genotypically through reduction in fitness to combat disease.

“Also, venomoid snakes seem to be living long healthy lives.”

Well, I am not so sure about that. Presumably this type of “surgery” is usually carried out once the snake has reached maturity. A “long-life” after such surgery might be more of a consequence of the snake’s condition PRIOR to surgery than after it. In any case, how much do we really know about the life span of reptiles – in particular venomous snakes? I believe that most of Australia’s species of large Elapids may attain ages in the wild in excess of 20 years as the norm. In one case in the western part of Sydney I observed the same adult Pseudonaja textilis repeatedly over 25 years until the site was destroyed for a factory complex. And this snake was no where near the known potential maximum size that has been recorded for this species. It is not inconceivable that Elapids may have life spans far exceeding the brief period since this “venomoid” business started. So, I rather doubt that such snakes are “living long healthy lives”.

Best Regards

Richard Wells

With all due respects, it seems that your answers are conjecture and probabilities. Non-the-less, I only wish to make the point that, it is obvious that a snake does not need to inject its digestive enzymes into its prey to have successful digestion: whether they are a venomous reptile or not.

I very well realize the complexity of reptilian venoms. I began research thinking that I may use venoms for taxonomic
relationships. No way, because of the reasons that you stated. Variations of venoms due to age, geography, sex and diet made my research impossible.

I was working under Dr. Brattstrom and he assured me that it was impossible with our current technology. That was 20 years ago.

Hi there Lachesis,

"it seems that your answers are conjecture and probabilities."

Well, maybe...but no more than the notion that ripping-out venom glands and ducts and changing the physiological functions of the reptilian endocrine and digestive systems is harmless.

"it is obvious that a snake does not need to inject its digestive enzymes into its prey to have successful digestion: whether they are a venomous reptile or not"

Sure, I'd go along with that alright....but if you will excuse a little more conjecture, what we regard as "successful" digestion may need qualifying. Much of our understanding on diet is pretty much one-dimensional I think - the snake looks healthy therefore it is healthy view is too easy to swallow. This view of "successful digestion" is often deficient even in the understanding of the short-term behavioural consequences of diet modification, and it certainly lacks any depth at all in regards to the long-term consequences of the alteration of dietary physiology upon the immunological and reproductive systems...with all due respect.

Oh, and by the way...I once met Bayard Brattstrom in Sydney many years ago and in my opinion he was a true scholar and a gentleman of the highest order. You should feel justly proud that you had the opportunity to study under him.

Regards

Richard Wells

I meant to say "Hi there Lichanura" - I even accidentally call my wife Lachesis so don't be offended.

RW

No offense taken. Lachesis, Lichanura, what's the difference.

Bayard loved Australia. We talked often, even after my degree was granted. We lost contact after he moved a few years ago. I am Maltese, and have about 250 relatives that live in Sydney and Melbourne. One of these days I will visit.

Thank you for an educational and entertaining "conversation".

Dave

I enjoyed reading this thread. It gave some stimulating thoughts to the idea of venom studies my organization is proposing at the university here. But being only in the beginning stages of this idea, I highly doubt much is going to come about during my time spent here (if at all). With an extensive herp inventory (at least for the size of our group and our means) just getting on the way and tons of educational shows, I find it difficult to come up with inexpensive research ideas that are worth the liability we would be imposing on a university whos angle of herpetology has long been dormant prior to the finding of this informal herp society full of ambition. But none the less, it was great to read through some great opinions on a topic that would formerly get people cringing before it got so much as a single response. Thanks

Ultimatly you should ask a Veterinarian knowlegable of venomoid surgery. Once removed completely removed, I do not believe that such tissue will grow back due to the fact that not all reptillian tissues are regenerative. I would imagine the same would apply to partial removal, although I am unsure. It may be possible for the existing venom gland tissue to triggor a cascade of cell proliferation and differentiation in the local surrounding tissue, in such a case partial regeneration would be possible but again check with someone knowlegable in this fieldf of surgery. I would say that I wet bite would still be possible if some of the venom gland tissue remains because the specialized cells which contain the active genes responcible for toxin production would still remain. As suggested by the work of Dr. Bryan G. Fry, these tissues originated from a variety of body tissues, from all parets of the body, and therefor I cannot say for certain that all of the toxin producing tissues are located in the venom gland alone. Venomoid surgery is terrable thing for these magnificent animals. These snakes should not be kept as pets and should only be kept by individuals with extensive training and for research purposes. In such a case you would not even be considering venomoid's. This proceedure is extremely stressful for the snake and could result in severe infection if done improperly! The venom glands are there for a reason! Leave them there! Get yourself a snake that wont kill you if a mistake is make! I hope this helps.

These snakes should not be kept as pets and should only be kept by individuals with extensive training and for research purposes.

I disagree, I think that a valid, serious interest, coupled with EXTENSIVE experience and preparation is what is needed. To say that only facilities and researchers should have access to venomous snakes is absurd, most of what they have learned was taught to them by private keepers, private keepers have more success with animals because they devote most of their time and money to care for them, where zoos and such treat them as attractions, when one dies they simply order up another one from a breeder or importer. Ive seen "professionals" from AZA accredited zoos kill snakes while assisting with a news photo shoot, the dummy put them in a CLOSED 5 gallon bucket on a hot sunny day, it was in the shade but the temp in the shade was over 105 degrees, some "professional". I told him twice that it was too hot, since I am only a volunteer I was not taken seriously, he was quite embarrased when he opened up one of the buckets to film a speckled rattler and it was in the final stages of a VERY unpleasant death. It was one of the few times I hated being right.
When someone dies from a "venomoid" bite that will be the end of it, no vet will risk the liability, and no herper in his right mind will risk "coat hanger" surgery.