Q: Dr. Krishna, I read your answer to the question, "What is the difference between venomous snakes and poisonous snakes?" 

the-difference-between-venomous-snakes-and-poisonous-snakes

I have another question on this topic: Can you drink snake venom? Does it cause  death if you drink it?

I am asking this question because I read a story where an Eagle catches a snake and flies to kill and eat it. The snake releases its poison in the sky which falls in a pot containing curd. And all the people who eat the curd die. And in the end when they go to Heaven, God tries to find out who is responsible for the death of these people. 

Krishna: :) Nice story.

 But let us approach this subject from a scientific perspective. While it may be theoretically possible to drink snake venom and live to tell the story, there are quite a few risks associated with such actions. Let’s discuss this  deeper to find out if you can drink snake venom and still survive.

Let us start with the snake venom's composition first. Snake venom is a white or yellow-coloured liquid which is produced in glands behind the snake's eyes and is pumped down a duct to the fangs when it bites down on something or someone. Snake venom comprises largely of proteins, enzymes and polypeptides. It is actually a type of saliva that can be lethal if it enters your bloodstream. It differs from poison that can kill you via touch, ingestion or injection. For venom to kill you, it must be injected in your soft tissue or bloodstream. This is exactly what a poisonous snake does. 

Snake venom

However, the situation is different when someone drinks snake venom. Since the venom is largely proteins and polypeptides, it gets broken into simpler substances inside our stomach. Our saliva, stomach acids and other enzymes work quickly to convert venom into digestible compounds. Some of it will be excreted, just like any other indigestible food item. This is what happens normally.

So, going by this logic, you will be safe if you drink snake venom. However, there can be several other scenarios and some risks associated with ingesting snake venom. Let us see what they are now. 

Small openings in the gastrointestinal tract – Our digestive system is pretty long, stretching up to 30 feet in length. If there are even any minor cuts along the way, the venom can leak into the bloodstream. This in turn can prove fatal. For snake venom to pass safely through your digestive system, there should not be any cuts, bruises or ulcers in the mouth, esophagus, small and large intestine, liver, pancreas, gallbladder and anus. You should also not have medical conditions such as leaky gut. Due to these risk factors, drinking snake venom can never be considered safe.

Allergic reaction – Proteins are among the primary causes of allergic reactions. So, if you drink snake venom, it may cause an allergic reaction. Since there have been limited number of documented cases on this topic, it’s not certain how serious the allergic reaction to snake venom can be. We can get an idea by looking at more common cases involving bee stings, where people have developed serious allergic reactions.

Allergy is an immune‐related disease and results from a hypersensitive immune response to harmless substances in the environment.

Overall, drinking snake venom does not seem to be a good idea, even though it may be theoretically harmless inside your stomach. But who knows what your digestive tract really looks like inside you or how your immune system treats the venom? So stay away from venom. Don't try to drink it. 

Q: What animals are resistant to snake or other  types of venom?

Krishna: The hedgehog (Erinaceidae), the mongoose (Herpestidae), the honey badger (Mellivora capensis) and the opossum are known to be immune to a dose of snake venom.

The question whether individual snakes are immune to their own venom has not yet been definitively settled, though an example is known of a cobra that self-envenomated, resulting in a large abscess requiring surgical intervention, but showing none of the other effects that would have proven rapidly lethal in prey species or humans.

Furthermore, certain harmless species, such as the North American common kingsnake (Lampropeltis getula) and the Central and South American mussurana (Clelia spp.), are proof against the venom of the crotalines,  and which they are able to overpower and feed upon. The chicken snake (Spilotes pullatus) is the enemy of the fer-de-lance (Bothrops caribbaeus), and in their encounters, the chicken snake is invariably the victor. Repeated experiments have shown the European grass snake (Natrix natrix) not to be affected by the bite of the European adder (Vipera berus) and the European asp (Vipera aspis), this being due to the presence, in the blood of the harmless snake, of toxic principles secreted by the parotid and labial glands, and analogous to those of the venom of these vipers. Several North American species of rat snakes, as well as king snakes, have proven to be immune or highly resistant to the venom of rattlesnake species. The king cobra, which does prey on cobras, is said to be immune to their venom.

The honey badger and domestic pig were found to have convergently evolved amino-acid replacements in their nicotinic acetylcholine receptor, which are known to confer resistance to alpha-neurotoxins in hedgehogs. Whether the pig may be considered immune is still uncertain, though early studies show endogenous resistance in pigs tested against neurotoxins. Though the pig's subcutaneous layer of fat may protect it against snake venom, most venoms pass easily through vascular fat layers, making this unlikely to contribute to its ability to resist venoms. The garden dormouse (Eliomys quercinus) has recently been added to the list of animals refractory to viper venom. Some populations of  California ground squirrel (Otospermophilus beecheyi) are at least partially immune to rattlesnake venom as adults.

And there are reports of even human beings developing immunity towards some snake venoms! The acquisition of human immunity against snake venom is ancient (from around 60 CE, Psylli  tribe). Research into development of vaccines that will lead to immunity is ongoing. Bill Haast, owner and director of the Miami Serpentarium, injected himself with snake venom during most of his adult life, in an effort to build up an immunity to a broad array of venomous snakes, in a practice known as mithridatism. Haast lived to age 100, and survived a reported 172 snake bites. He donated his blood to be used in treating snake-bite patients when a suitable antivenom was not available. More than 20 so-treated individuals recovered (1, 2, 3 ). Amateur researcher Tim Friede also lets venomous snakes bite him in the hope of a vaccine against snake venom being developed, and has survived over 160 bites from different species as of January 2016. (4)

^Footnotes:

^1."Farewell to these famous Floridians". Florida Trend. 19 December 2011. Retrieved 2 April 2012.

2. Rosenberg C (21 June 2011). "Bill Haast dies at 100; snakes were the charm for south Florida ce.... Los Angeles Times. Retrieved 16 October 2012.

3. Schudel M (18 June 2011). "Bill Haast dies at 100: Florida snake man provided venom for snake.... The Washington Post. Retrieved 16 October 2012.

4. Man makes deadly snakes bite him 160 times in hunt for human antido.... Independent.co.uk. 21 January 2016. Retrieved 7 July 2016.