"It was also discovered that the dilophosaurs could spit a distance of fifty feet. Since this raised the possibility that a guest in a car might be blinded, management decided to remove the poison sacs. The vets had tried twice, on two different animals, without success. No one knew where the poison was being secreted. And no one would ever know until a autopsy was performed on a dilophosaur - and management would not allow one to be killed."
- Michael Crichton, Jurassic Park
The ranks of venomous snakes have to include some of the most impressive snakes on the planet. The king cobra is a massive, powerful snake, capable of rearing up and looking its keeper in the eye with an intelligent, alert gaze. The whirling sound of a rattlesnake's tail in motion, whipping so fast that it can barely be seen, is one of the most memorable noises in the nature. Many venomous snakes have beautiful patterns and colors, from the elaborate geometric designs of the Gaboon viper to the startling, electric yellow of the eyelash viper.
If only there wasn't that whole pesky venom aspect of their care. "Hey," you can almost imagine some enterprising reptile keeper saying, "that gives me an idea..."
Venom is produced in a gland. Glands can be removed. Venom is carried to the fangs via ducts. Ducts can be severed. Some people put this information into practice and surgically remove the venom glands from their snakes. Such animals are called "venomoids."
(Some handlers try to draw the fangs of the snake instead, but fangs will grow back, which can pose quite a problem if the handler forgets when they last defanged their snake. Other people, especially snake charmers, would take the extreme of actually sewing the mouths of snakes shut. That's obviously pretty crazy and brutal, and we're going to assume that no sane person would think that's an okay thing to do. We'll focus on the surgical side only).
Removing a snake's venom glands has obvious safety benefits for hot keepers. Without its much fabled venom, a black mamba is just a big gray snake and it's bite no more serious to a caretaker than that of a black rat snake. Antivenom is so prohibitively expensive for many species, and not always effective. Keeper safety should come first, so why not just remove the primary factor of danger in the first place? Captive snakes are rarely fed live prey anyway, proponents point out, so what do they need venom for anyway?
Well, there is a reason that most snake handlers do not convert their snakes into venomoids... a few reasons, actually. First is the risk, stress, and (even with analgesics) pain that the surgery inflicts open the snake. Even more important is the future well-being of the snake. Venom has functions other than killing prey and fending off predators; venom also contains enzymes that the snake uses to help digest its prey. Critics suggest that venomoid snakes will have a compromised ability to gain nutrition from their prey. Oh, and there have been cases reported of snakes regenerating their removed venom glands. Surprise!
Pretty much every venomous snake I've ever seen in a zoo has its venom glands intact. In fact, almost all venomoids that I've encountered have been marked for private sale to pet-owners and collectors. The practice is generally frowned upon by most herpetologists I've met, who consider it a chance for irresponsible pet-owners to pretend to be bad-asses by swinging a (nominally) "safe" cobra around in their bare hands, or a showman who wants to let tourists hold a venomous snake for a photo-op. Many veterinarians will refuse to perform the procedure. Unfortunately, some people who decide to do the surgery do it themselves, first chilling the snake so that it will be too cold to resist during the procedure.
For a cobra or a rattlesnake, venom is as much a part of the snake's being as its scales and bones. Working with a venomous snake means working with the whole venomous snake. I tend to take a pretty liberal view of private hobbyists and owners with exotic pets as long as they meet very high standards of professional care, what I would expect of myself or any other professional zookeeper. To turn a snake into a venomoid because you want to feel like a tough guy or aren't prepared to accept that aspect of the snake means you fail to meet those standards.
You want to play safe, then get a corn snake. Leave hot snakes to those who can handle them.