Reptile & Amphibian Forums

On a few recent tv shows, I've heard more than one person say that monitor lizards are mildly venomous. On one show, Donald Schultz actually milked an Australian monitor. I don't know much about lizards, as I only keep snakes, but I found this very interesting. Are all monitor lizards mildly venomous? What effects come from an envenomation? Any info would be appreciated.

> On a few recent tv shows, I've heard more than one person
> say that monitor lizards are mildly venomous. On one show,
> Donald Schultz actually milked an Australian monitor. I
> don't know much about lizards, as I only keep snakes, but
> I found this very interesting. Are all monitor lizards
> mildly venomous?

At this point in time, the evidence is still sparse but the most parsimonious answer is that all monitors (and a number of related lizard groups) have mild venom. Venom has been observed in Komodo monitors (Varanus komodoensis) and lace monitors (Varanus varius), and symptoms consistent with a venom have been reported from desert monitor (Varanus griseus) bites.

> What effects come from an envenomation? Any info would
> be appreciated.

Compounds in the venom have been shown to act as vasodilators and anticoagulants. These serve to keep a wound bleeding, such that a monitor bite will not clot as readily. Large doses of vasodilators can also induce hypovolemic shock, as blood pools in the extremities away from vital organs. The latter effect is probably negligible in something as large as a human, but may be significant in the usual prey of a monitor lizard. Since hypovolemic shock can also be caused by blood loss, these two effects combined with a bite that produces deep lacerations to encourage bleeding may hasten the onset of shock in prey. This both aids in prey capture and can limit injury to a monitor from prey that aggressively defends itself.

The effects of monitor envenomation on humans is minimal. Monitor bites from Asian and Australian species do bleed freely, but the trauma from a monitor bite is usually not life threatening (save in the case of Varanus komodoensis) and the quantity of venom introduced into the wound is likely to be sufficiently low compared to our body mass that death from exanguination seems extremely unlikely. On rare occasions, anecdotal reports from monitor bite victims have described intense shooting pain at the bite location, or weakness lasting for about a day. Either of these may (or may not) be caused by venom.

Luke

>> Venom has been observed in Komodo monitors (Varanus komodoensis) and lace monitors (Varanus varius), and symptoms consistent with a venom have been reported from desert monitor (Varanus griseus) bites.

Thus far we have published our studies of Varanus acanthurus, V. komodoensis, Varanus mitchelli, Varanus panoptes rubidus, Varanus varius. Our paper currently under-review that examines a wide range of anguimorph lizards, including a wide taxonomical assortment of additional varanid species: V. albigularis, V. eremius, V. giganteus, V. gilleni, V. glauerti, V. gouldii, V. indicus, V. mertensii, V. mitchelli V. p. panoptes, V. prasinus, V. salvator, V. scalaris, and V. tristis.

>>
>>Compounds in the venom have been shown to act as vasodilators and anticoagulants. These serve to keep a wound bleeding, such that a monitor bite will not clot as readily. Large doses of vasodilators can also induce hypovolemic shock, as blood pools in the extremities away from vital organs. The latter effect is probably negligible in something as large as a human, but may be significant in the usual prey of a monitor lizard. Since hypovolemic shock can also be caused by blood loss, these two effects combined with a bite that produces deep lacerations to encourage bleeding may hasten the onset of shock in prey. This both aids in prey capture and can limit injury to a monitor from prey that aggressively defends itself.

Very nice summing up

>>
On rare occasions, anecdotal reports from monitor bite victims have described intense shooting pain at the bite location, or weakness lasting for about a day.

In addition to prolonged bleeding, these features have indeed been occasionally reported for human bites. Some small Australian species (e.g. V. baritji) also really sting at the bite site.

Cheers
Bryan

-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Venomics Research Laboratory,
Department of Biochemistry,
Bio21 Institute,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

I've been bitten by savs and ackies and it's not fun...but then again they have powerful bites, so I wouldn't have assumed the pain was from toxins (this would have been ~5-10 years ago). Amazing work.

>>I've been bitten by savs and ackies and it's not fun...but then again they have powerful bites, so I wouldn't have assumed the pain was from toxins (this would have been ~5-10 years ago). Amazing work.

Pain certainly can result from the mechanical damage but the stinging/burning is a different flavour entirely and due to the toxins.

Just shows goannas are even cooler than we already thought

I'd have said the ackie bite stung mildly, kinda like when you get one of those small cardboard cuts or something. Whereas the sav bite(s) felt like a clamp studded with tacks was being tightened down HARD. And then he tried to twist around to start eating...oh god ow. Of the two...I'll take the ackie any day

Again, it's impressive work man I gotta get my hand on your work on Gila venom (I know the PDF's freely available, I just gotta print and read it). What does this suggest for relations between heloderms and varanids? I know that they're commonly regarded as closely related but I've never read *why*.

>>Again, it's impressive work man

Cheers for that

>I gotta get my hand on your work on Gila venom (I know the PDF's freely available, I just gotta print and read it).

http://www.venomdoc.com/downloads/2010_Fry_Heloderma.pdf

>What does this suggest for relations between heloderms and varanids? I know that they're commonly regarded as closely related but I've never read *why*.

Genetically they are part of the same lineage: the Anguimorpha lizards. Basal to Varanus is Lanthanotus and then basal to them is Shinisaurus. These three collectively are sister group the the clade made up by Heloderma, the various anguiid lizards and Xenosaurus. The next paper looks at the changes in glands and toxin in the various lineages.

Cheers
B
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Venomics Research Laboratory,
Department of Biochemistry,
Bio21 Institute,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

>>Very nice summing up

Thanks, Bryan. This is fascinating work you are doing, on an amazing group of lizards.

Luke

I am not really updated so much on the classification between venom and or bacterias that may attribute to the demise of prey items. I always believed that venom is from a gland specifically manufactured for survival of the predator [helodermas] and the quick killing of their prey. Bacterias have been noted in Komodo dragons for years. Here in the states a CB komodo dragon put its care taker in the hospital for a septic infection for 2 weeks. I think many people were surprised how a CB monitor that had never eaten carion or any other really nasty food items could pack such nasty levels of bacteria. All monitors carry bacterias that aid in killing as seen in komodo dragons. The footage I seen on an adult komodo dragon in the wild showed how this dragon ran up to an adult water buffalo and inflicted one bite, from then on the dragon backed off but never let the buffalo out of its sights, within about 8 hours under the conditions of heat/moiture levels the bacterias infected the buffalo to the point that is was just another day at the office for the komodo to run up and tackle this weakened beast and actually started to eat it alive. Very brutal to see but just mother natures plan of survival for the komodo.
Bob
www.herphatch.com

Have a read of this paper to see that the bacterial hypothesis was scientific voodoo. The komodos, and all other varnids, have a very large venom gland indeed. The obvious bulge on the lower jaw of all monitors is in fact that gland

http://www.venomdoc.com/downloads/2009_Fry_Komodo&Megalania

here are two other papers on the subject

http://www.venomdoc.com/downloads/2006_BGF_Nature_squamate_venom_press.pdf

http://www.venomdoc.com/downloads/2009_Fry_Toxicofera_review.pdf

Feel free to ask any questions you might have after you read them

Cheers
Bryan
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Venomics Research Laboratory,
Department of Biochemistry,
Bio21 Institute,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

Here is one of our MRI (magnetic resonance imaging) of the venom glands of the komodo dragon. The pink/red is the venom gland, the yellow the mucous. The cross section shows the very large central lumen for storing the liquid venom and the transverse shows the ducts that lead up to thread between adjacent teeth.

-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Venomics Research Laboratory,
Department of Biochemistry,
Bio21 Institute,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

Nice work, I did not read all of the links you posted but what leaves me wondering is how/why has the venom glands of varanus eluded science for so long and the helodermids were recognized many years ago? Its not like they are to far apart from one another it seems?
Thanks,Bob

>>Nice work, I did not read all of the links you posted but what leaves me wondering is how/why has the venom glands of varanus eluded science for so long and the helodermids were recognized many years ago? Its not like they are to far apart from one another it seems?
>>Thanks,Bob

A question I have thanked my lucky stars about.

>>On a few recent tv shows, I've heard more than one person say that monitor lizards are mildly venomous. On one show, Donald Schultz actually milked an Australian monitor. I don't know much about lizards, as I only keep snakes, but I found this very interesting. Are all monitor lizards mildly venomous? What effects come from an envenomation? Any info would be appreciated.

As for Don's 'milkings', I have to clarify this. He didn't actually milk them. It is a much more tricky process than milking a snake. He did a mimicry of it for the camera. He also, I have to point out, dramatically sensationalised the danger from the bite. They are of trivial human concern in regards to their venom. At no point should they be lumped in the same category as venomous animals such as cobras. Just because they have venom does not mean they should be considered as 'venomous' in the legal perpective in regards to laws against the keeping of venomous animals. I have gone to great pains to make this clear (his show unfortunately went quite the other direction).

This is not to say significant damage cannot result from the teeth, which is very much the case.

Here are links to some of our lizard venom papers:

http://www.venomdoc.com/downloads/2006_BGF_Nature_squamate_venom_press.pdf

http://www.venomdoc.com/downloads/2009_Fry_Komodo&Megalania

http://www.venomdoc.com/downloads/2009_Fry_Toxicofera_review.pdf

http://www.venomdoc.com/downloads/2010_Fry_Heloderma.pdf

Please don't hesitate to ask any additional questions you might have

Cheers
Bryan

-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Venomics Research Laboratory,
Department of Biochemistry,
Bio21 Institute,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

Thanks SO much for the info!

I'd been wondering about that as well. Donald's doing a publicity stunt in the next month or so where he's staying in a glass box full of venomous species for 10 days.

I felt bad for the poor emu in the first episode!

~jenny
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"We call them dumb animals, and so they are, for they cannot tell us how they feel, but they do not suffer less because they have no words."
- Anna Sewell (1820-1878)

Thank you, Luke and Dr. Fry, for all of the great info. I was a bit hesitant to ask this question because of the legal situation, but curiosity got the best of me...lol. I am facinated by venomous animals, and try to learn all I can about them. I plan on taking a look at those papers when I have some time. As far as AP goes, I know a lot of their shows are sensationalized, and do more damage to our hobby than good alot of the time. But, I love watching and learning about the many beautiful reptiles of the world, and aside from the occasional show on NatGeo, AP is my only option.

P.S. I love that picture with the komodo dragon, I hope to one day be able to see one of these incredible animals in person one day.

Brian
1.1 redtail boa
1.0 ball python
0.0.1 green tree python
0.1 amazon tree boa
1.2 eyelash viper

Brian I have to strongly suggest making a trip to St. Augustine Alligator Farm in Florida. It is one of the most BEAUTIFUL places on the planet for me with their amazing crocodilians but also their komodo who is STUNNING!

St Augustine Alligator Farm

-----
Cindy Steinle
PHFaust
Email Cindy
Visit kingsnake on Facebook!
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Definately
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Venomics Research Laboratory,
Department of Biochemistry,
Bio21 Institute,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

I have worked with water monitors for about 16 years I have kept other species but Waters are what I have primarily worked with. as a result I of course have been bitten quite a bit over the years mostly minor bites but a few major ones as well. I have recently seen the reports of venom glands being found in V. komodoensis and found it interesting that you guys were mentioning the presence of anti-coagulants in the toxins of Komodoensis and a few other species. The one consistent thing I can tell you about salvator bites is that they will bleed for hours (last bite I got about 2 months ago bled for about 4 hours and it really wasn't that bad). The wounds bleed much longer than the bleeding you would receive from a normal wound with comparable damage. I have been convinced for years that there is some sort of anticoagulant property present in their saliva ( I almost reluctantly refer to it as venom in the true sense of the word...I think of it being more like the toxic properties found in the saliva of some of the natracine snakes.). I do have a good account of the pan you are talking about however. In 2001 I was bitten by a 4.5' male salvator on my right thumb. It had an arthritic problem and I was removing it from it's enclosure to take it to the vet for a weekly exam. I believe it had figured out the weekly pattern and was reacting to the anticipated stress of being removed from it's environment and reacted accordingly. The bite went right through to the bone on the top of my right thumb it was not as deep on the lower part of my thumb but still signifigant. Almost immediately upon being bitten I noticed the excruciating pain that has been referred to here. The other thing I remeber was immediatley after being bitten I put the lizard back in its cage and went to clean and treat the wound. Walking into my kitchen to wash the bite the florescent lights in the kitchen suddenly blinded me (it's the best way I can describe it, it was on unusual experience.) and the pain got much worse and I actually got a bit dizzy. I am not sensetive to florescent lights as some people are and there was not that much difference in light levels from the two different rooms. It did occur to me at this point in the events that there may be some sort of toxic property to there saliva that was causing this pain and the unusual light sensitivity I was experiencing at that point. I had worked with salvators long enough at that point to be aware of the anticoagulant properties present in their saliva but this was a unique experience. Being a stubborn individual and not wanting to miss the vet appointment I retrieved the monitor and made the vet appointment. Adding up the time to and from the vet (about 2 1/2 hours as well as the time finding somewhere to treat the bite (after a lot of convincing from my wife and the vet both.) and the 2 hour wait time at the emergency room the bleeding finally subsided. The wound probably bled for 6 hours. Over the years I have had other serious bites but never experienced this type of excruciating pain or light senstivity. As I said I have had many other bites from water monitors and the long bleeding time is pretty consistent with them, Bites I have received from other species of monitor including a Niloticus I owned for 15 years(which oddly enough I almost never got bitten by.) Rudicolis, indicus and some others have never exhibited the amount of bleeding I have observed from salvator bites. Another thing I have always noticed and have pointed out to others who notice when I get bitten by a salvator is how quickly the bites heal compared to other wounds. I do not know if it has to do with a component in their saliva or just the amount of bleeding the bites caused, but I have noticed the difference in healing times to the point of considering physically doing a comparable wound to myself after being bitten just to document the difference in healing times.
Like I said this is obviously anecdotal evidence but having had my own hypotheses on water monitor saliva over the years based on my own experiences I find the current research on the subject fascinating.

>I think of it being more like the toxic properties found in the saliva of some of the natracine snakes

Which is also venom not saliva. Here is a link to one of our papers on snakes that looked at a wide variety

http://www.venomdoc.com/downloads/2008_BGF_Evolution_of_an_Arsenal.pdf

The same gland that is responsible for the venom in cobras and rattlesnakes, is present in just about all of the other advanced snakes, in varying size, and many of the exact same toxins are present too.

Cheers
Bryan
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Venomics Research Laboratory,
Department of Biochemistry,
Bio21 Institute,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

Saying that everything is venomous will just lead to more anti-reptile ownership laws. If its "venom" won't kill me then its saliva as far as i'm conserned.

>>Saying that everything is venomous will just lead to more anti-reptile ownership laws.

We make a very clear point at every opportunity that venomous is not necessarily dangerous. All spiders, for example, are venomous but only a handful are dangerous

> If its "venom" won't kill me then its saliva as far as i'm conserned.

The key to understanding this is the evolutionary history of the glands involved. Venom glands are distinct gland arrangements from saliva glands and the specific proteins secreted are very different.

As for lethality, by your definition you would be excluding many of the vipers and elapid snakes of the world as they are not likely to be lethal.

Cheers
Bryan
-----
Dr. Bryan Grieg Fry
~~~~~~~~~~~~~~~~~~~~~~
Venomics Research Laboratory,
Department of Biochemistry,
Bio21 Institute,
University of Melbourne
~~~~~~~~~~~~~~~~~~~~~~
http://www.venomdoc.com

....Because you are absolutely correct. These lizards do not contain venom for any USEFUL sense of the word. The toxins present in the saliva have independent functions from venom. A type of epiphenomena without any testable function. This work masks, not illuminates the true diversity with squamate evolution.

AS SCIENTISTS OUR LANGUAGE SHOULD NOTE THE DIFFERENCES, NOT ASSIMILATE THEM! THESE LIZARDS ARE NOT VENOMOUS. PHARMACOLOGICAL PROPERTIES ALONE DO NOT MAKE A VENOM. IF THIS WERE TRUE US HUMANS WOULD BE VENOMOUS.

Your symptoms are fairly common to experiences of most animal bites (humans included). The properties of oral secretions are a function of a lifestyle. These monitor lizards do not live a venomous lifestyle, and also lack the behaviors to accompany such a weapon. THEY ARE NOT VENOMOUS.

By the way Brain, what is a venom? How many toxins are necessary? One, 10, 100? Why do all our conversations end up missing?

I have a suggestion. Instead of generalizing everything and grouping all reptiles as venomous, why not go the other way and be more specific as to what is really going on? You know calling them what they are, anticoagulants, immobilizing proteins, oral lubricators ect?
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"Relax, Don't Worry, Have a Homebrew!" Charlie Papazian

I was wondering when you'd show up and make the same tired (and discounted on countless previous threads) statements that you've been trotting out arguing against venom in non-front-fanged snakes and now an inability to recognise it in lizards. When you have something new and relevant to contribute, I'll answer that then. Until then, enjoy writhing at Kardong's feet in a frenzy of self-abasement.

Please, keep strokin yourself. Your contributions are hardly new, you have just used new technology to employ an old idea, and used taboliods to popularize it. I owned you before in the previous threads. The conversations were good, yes but for some reason those actual CONTRIBUTIONS to this conversation are GONE! In fact, there is not a single record of any of our previous conversations...wonder why?

Just when I was starting to think we had become friends....Well, I will just pretend then.

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"Relax, Don't Worry, Have a Homebrew!" Charlie Papazian

I owned you before in the previous threads. The conversations were good, yes but for some reason those actual CONTRIBUTIONS to this conversation are GONE! In fact, there is not a single record of any of our previous conversations...wonder why?
>>
>>Just when I was starting to think we had become friends....Well, I will just pretend then.
>>

HI Dobry,

We do archive our posts, so when searching what may work better is to select the archive year. Such as entering your name in the search field your name and then under Search in choose a year for example 2005 rather than current. This is done on each forum separately, so you would need to look at each forum you have debated each other in the past.

Hope that helps!
-----
Cindy Steinle
PHFaust
Email Cindy
Visit kingsnake on Facebook!
Follow Kingsnake on Twitter!

Thanks Cindy, but those posts have long been deleted for unknown reasons. I always searched by poster. You can click on any member and search all the posts they have ever posted. Not a single trace of any of these conversations in either my or Brian's archive.
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"Relax, Don't Worry, Have a Homebrew!" Charlie Papazian

>>Thanks Cindy, but those posts have long been deleted for unknown reasons. I always searched by poster. You can click on any member and search all the posts they have ever posted. Not a single trace of any of these conversations in either my or Brian's archive.
>>-----

You mean like these?
http://forums.kingsnake.com/viewarch.php?id=803035,803035&key=2005
http://forums.kingsnake.com/viewarch.php?id=1561769,1561769&key=2008

Killer.....you found some of them, however there are more threads than that.
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"Relax, Don't Worry, Have a Homebrew!" Charlie Papazian