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Venomoids - A Practitioner's View
Reproduced with permission of Raymond Hoser
Part 2
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.