Originally published in Hard Evidence (November 2004) 4(6):25-29, with photos of an operation on an adult Sydney Death Adder (Acanthophis antarcticus), including removal of glands, silicone implant insertion (both) and suturing.
For more than 20 years, reptile enthusiasts have dreamt of making dangerously venomous snakes harmless.
Several reasons actually.
Besides the obvious one of public safety in that "fixed" snakes could be shown without risk, the desire to render snakes harmless to humans was also sought for the snake's benefit in that they could be effectively "deshackled" from pinning and hooking, both handling methods giving snakes pain, and instead free-handled mid body in the same way harmless snakes usually are, giving the snakes less stress and hence increasing their long-term health and longevity
Fang removal isn't an option as these regrow and so the focus was then on the surgical removal of venom glands.
In recent years and with the aid of modern medical techniques, herpetologists and veterinary surgeons have actually attempted to do this, in that they tried to surgically remove the venom glands and leave the snake alive and intact.
Until early 2004 the operation had been trialled with mixed results in the USA, UK and at least once in Australia. The only reported Australian attempt was by Sydney herpetologist David Millar and resulted in two Tiger snakes dying prematurely and hence was an abject failure.
In the USA where more attempts were done at the operation, the results were somewhat better, some vets reported up to a 50% success rate, in that nearly half the snakes operated on actually survived.
These snakes became known in the trade as "Venomoid". Due to the high mortality of snakes, the procedure was generally regarded as cruel and shunned by most reptile people.
The operation procedure was essentially as follows:
A snake is sedated, usually by gas, such as Isoflurane as this is least problematic in terms of dosage. (Injectable sedatives are unreliable for reptiles and the result is often under or overdose, the former leading to an unsedated reptile and the latter in death).
Once sedated, the snake is laid out on the operating table, usually tied down with stockings, with gas tubed into the windpipe to keep the reptile sedated.
The snake's head is then cut open and the venom glands are removed.
Due to the siting of the glands at the top of the back of the head, this area is cut and then stitched up after the operation to remove the venom glands.
Notwithstanding the best veterinary methods, mortality of snakes tended to be due to sedation mishaps or more commonly due to post-operation infections, as well as a smattering of stress-related matters such as non-feeding leading to a downhill spiral in health until death from secondary infection.
Using lateral thinking, Australian herpetologist Raymond Hoser analysed the venomoid operating procedure as known and tried to eliminate all the known problems likely to cause death.
Most importantly however was the simple realisation that it'd be possible to remove the venom glands by going through the roof of the mouth (including through an intervening wall of muscle tissue) instead of through the top of the skull.
Analysis of (mouth-rot) infections in snakes mouths and their successful treatment by hobbyists with generic antibiotics showed that the snake's mouth had a tremendous ability to heal and at high speed.
This contrasted sharply with the fact that snakes external scales have limited healing ability and are constrained by the shedding cycle which for most snakes usually runs only every two to three months.
This contrasting fact alone is what pointed Raymond Hoser to look seriously at doing a venom gland removal operation by going through the roof of the mouth.
There were other factors favoring the method of going through the roof of the mouth.
Unlike scales on the top or side of the head which would be sunken after an operation, complete with wounds and naturally attract dust, dirt and even coagulated blood at the incision site, the top of the mouth when sutured would naturally not attract these things.
Being inside the mouth, the wound would in effect be protected from environmental dusts and hazards. Being on the roof of the mouth, the pus and other debris would naturally drain away from the wound and down the throat or out of the sides of the mouth.
The net result of course would be a self-cleaning wound.
However the idea of operating on the roof of the mouth (cutting it) was unusual in snake surgery in that it presented a new logistical problem in terms of sedation.
The method of choice (gas) was no longer viable. In virtually all other reptile operations, the sedation means (gas and/or tube) is not in the way of where the cutting is being done. However in the planned operation, the snake would have to have it's head affixed to the surface upside down (to yield the area to be cut) and the tube of gas would have to move into the air and bend downwards (in a virtual right-angle) in order to run down the windpipe which sits at the base of the rear of the mouth.
The logistics got worse when it is realised that the mouth would also have to be held open by some means.
To make things worse, this tube would run over the general area to be cut; the venom glands being sited literally to either side of the tube and within millimeters, making cutting problematic, especially as the flesh is parted to yield the tubular venom glands.
As a result of this technical difficulty and general inertia at trying new things, the idea of venom gland removal by going through the roof of the mouth had until 2004 been rejected by herpetologists and veterinary surgeons and had not been tried previously.
This did not however dissuade Raymond Hoser from trying to deal with the other technical issues facing the idea of internal cutting to remove the venom glands.
Using more lateral thinking, another foolproof method of sedation was employed.
Known as cold torpor, the reptile is cooled to about 5 degrees Celicius, whereupon it is sedated and it's ability to feel pain effectively removed.
During winter months reptiles naturally find themselves in this state quite often (in colder areas) and often for several hours a night.
Cold torpor fell out of favor with the veterinary community about 15 years ago, following the development of gas sedation (preferred for the reasons set out above and below), and also due to the speed and ease with which it can be done.
Sedation of reptiles safely using cold torpor takes far longer than using gas (usually about 30-60 mins versus less than five) and there is an obvious margin for error if a reptile is cooled too far (frozen and killed) or not far enough (still active). The exact temperature suited to the reptile is also species dependent, making cold torpor more tricky and time consuming for veterinary surgeons, in that sedation by gassing is literally a one-size fits all process.
Some years back a benchmark text by US Veterinary Surgeon Frederic Fry also said that cooling reptiles left them with long term disablement in terms of lack of appetite and susceptibility to infections.
This actually relates to captive reptiles housed for long periods in suboptimal cages, with cooler than optimal ambient temperatures (at all times) and not cold torpor as a means of short term sedation, although the confusion remains to this day and Fry himself may have had this confusion.
That a reptile could be sedated by cooling was only part of the problem.
The reptile also needed to be maintained this way and to do this a new technique was also developed by Raymond Hoser.
Instead of a hit and miss process using ice-cubes as used by past practitioners (in the 1960's and 1970's when cold torpor was widely used), a more precise method was developed.
Wet, frozen and partly defrosted towels were used to cover the sedated snake and hold it at the appropriate temperature for the duration of the operation. This method allowed sedation for as long as was needed and the ability to remove sedation as soon as the operation was completed.
The towels were used to cover the posterior part of the body (not the head), allowing an unfettered and unimpeded view of the area to be cut. No other sedation method allowed this, making this cold-torpor the method of choice for the planned operation.
As a side benefit, cold torpor reduced bleeding when cutting, negating the need to cauterize the blood vessels with a soldering iron (as usually done), thereby reducing scarring and scar tissue complication risks post operation as well.
Maintaining cold torpor, any excess blood that appeared during the cutting was removed with an icy water syringe.
Sedated snakes still move involuntarily, particularly at the tail end and hence snakes must be tied down by some means. Recommended by most veterinary surgeons was stockings or similar, but tested instead by Raymond Hoser (on dead snakes) was sticky tape and this was preferred as it's grip was better and did not have to be as tight around the snake's body or vital organs. The tape could be removed post operation with ease and without causing injury to the snake or it's scales.
The head was affixed by rubber band to a flat surfaced plank of wood (lower jaw) and the upper jaw affixed in an open position by use of a hard wire frame (from a coat hanger) connected to two inward facing nails.
No such operational set-up had ever been used before.
Several sets of nails in the same part of the plank allowed for bands to be moved to expose or cover fangs and adjacent areas and allow the lower jaw to be fixed down at all times when cutting.
The head had to be held rigid at all times to make the cutting easier and more accurate.
On each side, the roof of the mouth was cut through the muscle to yield a venom gland, which was gouged loose from the adjoining tissue and cut at either end from the attached muscle ball (Posteriorly) and venom duct/fang region (anteriorly). The wound was then sutured up, before antibiotics were liberally applied.
The snake was then allowed to recover.
Other unique logistical issues such as sterilizing surfaces, tools, best sutures to use, etc, were dealt with as well and included further previously unused innovations.
Before the first operation was done on a live Tiger Snake, dummy runs were done on road-killed snakes so as to enable to planned procedure to be mastered and any minor glitches ironed out.
Every aspect of the operation was meticulously tested several times before the first operation on a live snake, by which stage the theory and practice showed that the procedure was foolproof and reliable in terms of removal of the snake's venom glands.
The first operation on a young Tiger Snake was a success. It showed no signs of pain at any stage, either during or post operation and ate shortly after.
The rapid recovery (total healing in days), was anticipated, but still the speed of recovery was a shock, when compared to the litany of failed venomoid operations by others in the past.
Due to the trouble-free first operation, several more snakes were operated on using the same method (or minor variants of it) and all were similarly trouble free.
Within weeks, 17 deadly snakes had been surgically rendered harmless and all made perfect recoveries within days of the operation.
Ways to short-cut the process and make operation times faster were developed and used.
Larger snakes, such as big Tiger Snakes and Death Adders had silicone implants placed in their heads to replace the venom glands and they too made perfect recoveries.
For the first time ever, large numbers of valuable snakes could be made venomoid without fear of mishap.
The snakes were used for public displays for some time before Raymond Hoser announced that all had been surgically fixed via a paper in the UK journal Herptile.
Countless other reptile people and members of the public had by that stage seen these snakes and been unaware that they had been surgically fixed. Put simply, the operation was not detectable.
The revelation that deadly snakes could now be safely made harmless in a now simple and routine procedure came as a bombshell in the reptile world.
Internet forums and lists were flooded with discussions in terms of this brave new world of venomoid snakes. Many correspondents maintained disbelief that the venomoid procedure on snakes could have been modified to become risk free for the snakes.
While the initial aim of the operation was to make deadly snakes used in public displays harmless (for safety reasons), the operation has had numerous other positive spin offs.
For the captive snakes themselves the operation to remove the venom glands has had unexpected benefits. Normally deadly snakes are handled forcibly with pinning sticks and grabbed tightly behind the head. This is because a bite can be fatal and any other handling method leaves that risk open.
Surgically rendered harmless snakes don't need to be handled this way, instead being able to handled like harmless pythons. This kind of handling, (mid body and supporting the snake and not restraining the head and neck) is pleasant to the snake and results in far less ongoing stress and cruelty to the snake in terms of it's handling and rapidly manifests as a less stressed and more healthy snake.
Unstressed snakes feed more reliably in captivity, breed more readily and so on.
Contrary to reports that snakes need venom for digestion (including in many books), this isn't so. Venom's only real use is to kill food. As captive snakes are fed only already dead food, the non-venomous state of these "venomoid" snakes is a non-issue. The venom glands are otherwise a non-essential organ and their removal has no impact on the snake's ongoing welfare.
The Sensation Caused by the new venomoid snakes.
In terms negatives of the operation or negatives to the snakes there were none.
Notwithstanding this, Raymond Hoser's ever reliable critics soon came out of the woodwork with a litany of alleged woes and crimes committed by Raymond Hoser. These were in the main persons adversely named in the Smuggled books and/or their close friends.
One claim was that the new Hoser procedure was cruel as no chemical anaesthetic was applied to the snakes. Coupled with this was a similar claim that cooling the snakes was also cruel.
Noting that snakes in the wild state cool to five degrees or less on a daily basis in winter months in cooler regions, the cruelty in cooling claim started to look odd.
Furthermore it is common knowledge that reptiles that are cool have reduced or no sensations of pain. This fact is well-known and documented in all major texts and commonly manifests that reptile keepers must place wire cages around heaters and lights in snake cages as the snakes will when cold simply move up to the heat source and give themselves life-ending burns as they try to warm up their cold bodies.
Put simply, cold snakes don't feel pain, even when the pain indicates something life-threatening.
The herpetological literature is riddled with cases of pythons and other snakes that have killed themselves by sitting on light bulbs when cold.
Furthermore, snakes are pre-adapted in terms of getting internal mouth injuries, such as from a struggling mouse that is alive for three or more seconds after being bitten and held in a snake's mouth. Hence post operative pain in terms of soft tissue injury is automatically less than such that may occur from a routine feeding on a live rodent.
David Williams (a convicted and self-confessed criminal and wildlife smuggler adversely named in Smuggled (1993) and Smuggled-2 (1996)), true to form SPAMMED the internet with numerous false claims and generically condemning the venomoid procedure. However the irony of this was that a year earlier, he'd himself botched an attempt at venomoid surgery on a Taipan, in a failed operation in which he attempted to remove a single venom gland.
The final proof of the success of the new Hoser venomoid procedure was that within two months of details of the operation being published, (Australia's first ever successful venomoid operations) Hoser had been invited to give lectures at several scientific societies, had already fulfilled more than 20 requests to show the said snakes at public meetings and received more than 100 other requests to do the operations on other people's snakes, including at some of Australia's best known zoos.
Hoser declined all requests to operate on other people's snakes on the basis of liability issues (as in what happens if a person confuses a "fixed" with a "non-fixed" snake, which is easy), and so on, although by publishing the details of the operation, others minded to do such operations are now in a position to use a foolproof template.
Hoser has no short term plans to do further operations as all snakes needed for public displays have now been "fixed". These include, Black, Brown, Tiger, Copperhead and Death Adder.
Outside Australia and as a result of the fact that the Hoser method now makes venomoid operations safe and effectively painless for snakes, the demand for these operations has skyrocketed.
Non-reptile people are likely to see this demand manifest in an increasing usage of deadly snakes in TV shows and movies as actors take advantage of risk-free handling of snakes that in the "real world" are very deadly.
The paper detailing the venomoid procedure (including photos) is now on the internet at:
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