Snake Bros Keep Getting Bitten by Their Lethal Pets. Only Zoos Can Save Them

The first thing Chris Gifford thought as he felt a fang sink into his skin was: I’m going to die. The second: I need to start a timer immediately.

That day in 2021, Gifford was cleaning the enclosures of the several dozen snakes he kept at his parents’ home in Raleigh, North Carolina. Nearly every snake in his possession was both venomous and native to distant corners of the world. Sharp-nosed vipers, eyelash vipers, forest cobras—every one of them beautiful, and many of them lethal.

So too was the 7-foot-long, electric-hued western green mamba that had just latched onto its enclosure’s swing door as Gifford attempted to pull it out with a hook. The snake then lunged off and bit into Gifford’s hand, unleashing a deadly neurotoxic venom into his body.

“I dropped the snake,” Gifford says. “I dropped the hook. I’m like, ‘Oh man, I’m probably dead.’ This is a very toxic, fast-acting venomous snake.”

As Gifford, then 21, hurried to re-hook the mamba and secure it, he felt his hand begin to tingle ominously. Gifford didn’t know precisely how long he had, but was certain that without help he would be dead in hours. His life would depend on a vital resource: antivenom, which was tucked securely away at the unlikeliest of places—a zoo and botanical garden hundreds of miles away.

That’s where the Antivenom Index, a little-known directory that for half a century has connected Americans bitten by venomous exotic pets with the zoos that can save them, comes in. Generally speaking, the best way to treat the most life-threatening snakebites is with antivenom made using venom of the same species. The process begins with extracting venom, often by milking drops of toxin from the fangs of a snake. The venom is then injected into an animal, like a horse or a sheep, to spur the development of antibodies. It's finally transformed into a substance that can halt the original venom’s effects in humans.

Zoos that house deadly snakes stock the corresponding antivenom in case a keeper has an accident—and so it’s zoos that get the call when a civilian has a mishap of their own.

It was the Houston Zoo that provided antivenom to save a man bitten by his pet monocled cobra. A man bitten by an African pit viper received antivenom from the Virginia Aquarium and the National Zoo in Washington, DC, while another man bitten by a similar snake had a folder instructing doctors to call the Milwaukee County Zoo for antivenom in case he received a bite. A zoo in Seattle has provided antivenom in at least eight cases in the Pacific Northwest and Canada, including once for a puff adder bite in Portland. In one infamous case, a visitor to the National Zoo broke open an enclosure and stole two Gaboon vipers, one of which bit him soon after—for which he was treated with antivenom from zoos in Baltimore, New York City, and Philadelphia, as well as the recently robbed National Zoo.

The legality of venomous pet ownership varies widely by city, county, and state. But for those interested in taking it up, acquiring specimens has gotten steadily easier. Advances in snake husbandry mean that many once-rare species are now readily found in captive-bred populations. Snakes can be bought everywhere from reptile shows and breeders to online classifieds and pet stores, some of which ship venomous offerings around the country. Individual snakes rarely cost more than three figures.

And yet, snakebites are still rare in the United States: The National Poison Data System’s 2024 annual report listed a little north of 5,000 bites from venomous native species that year, with just 81 bites—of which at least 57 were venomous—from exotics.

But when the worst happens with an exotic snake, most hospitals are unprepared.

American medical facilities might be equipped with antivenom for native species like copperheads and cottonmouths, but they’re exceedingly unlikely to have the ability to treat bites from snakes whose natural ranges are farther afield. Venom from the most perilous exotics can take effect within minutes, in a nightmarish crescendo of symptoms depending on the snake and what kind of venom it possesses. Vomiting. Excruciating pain. Shock. Internal bleeding. Blistering. Organ shutdown. Paralysis. Suffocation. Death.

Once a patient arrives at an emergency room, hospitals contact their regional poison center, which in turn boots up the index, where zoos across the country voluntarily list which antivenoms they stock and in what quantity. And somewhere, whatever the hour, a keeper’s phone starts to ring.

Leslie Boyer, a medical toxinologist and professor emerita at the University of Arizona, spent two decades as the director of the Antivenom Index. After a rash of exotic bites in Oklahoma in the 1970s ended with a zoo providing antivenom, the idea emerged to approach zoos around the country one by one to ask what they had on hand and if they’d be willing to provide it to the public.

Early editions of the index were a tabbed notebook. “I still have some of the original versions of it,” Boyer says. “You would go through, laboriously, by hand, turning the pages, and it would say ‘see page 27,’ like one of those find-your-own-ending books, and then you would put in a phone call, because the last section in the Antivenom Index was the home phone numbers of zookeepers.”

In 2006, Boyer and Steven Seifert, then a medical toxicologist at the University of Nebraska, partnered to bring the index online, where it remains today. Now, nearly 90 zoological organizations list their wares.

Gifford, the North Carolina man, had been comparatively lucky, as only one of his mamba’s fangs had pierced his skin. By the time he reached a nearby hospital, Gifford's hand was swelling and creeping paralysis was causing his eyelids to droop. The Antivenom Index was activated, and South Carolina’s Riverbanks Zoo, about 200 miles to the southwest, had the antivenom he needed. Just 30 minutes after the mamba’s bite, Gifford was struggling to breathe as the paralysis started to affect his diaphragm.

“It feels like you’re drowning,” he says.

Keepers at the Riverbanks Zoo packed 10 vials of antivenom on ice and sent them on a helicopter. Just as Gifford’s timer hit the six-hour mark, the hospital began administering the first of the vials. “Almost immediately, I could feel myself breathing,” Gifford says. He left the hospital some two days later.

If you’re bitten by a venomous snake in the northeastern United States, odds are good that you’ll be treated with vials of antivenom nestled in a refrigerator in the back room of the Bronx Zoo’s reptile house. The zoo collaborates with the nearby Jacobi Medical Center, whose dedicated snakebite response team makes it a rarity among US hospitals.

Inside the refrigerator are boxes, bins, and bags of the delicate glass vials that are often the difference between life and death. Shelves are lined with jars full of antivenom for Indian species and the North American coral snake, and lavender cartons with images of a poised king cobra. In all, the Bronx Zoo stocks 25 different antivenom varieties, many of which are polyvalent, meaning applicable to multiple species.

The refrigerator is surrounded by empty coolers awaiting a future emergency. Four times a year, the zoo runs a full-scale drill with its herpetology staff, in which a keeper simulates the moments after a bite by hitting an alarm. From there, the team races to join the keeper and get the right antivenom into a cooler. A recent drill concluded with a real-life police car ride to Jacobi and the faux-administration of the antivenom. The “bitten” keeper was at Jacobi in just 10 minutes, with antivenom “running” in 20.

“The primary purpose for us keeping antivenom here is for the safety of our staff,” says Kevin Torregrosa, the zoo’s curator of herpetology. Indeed, a staffer’s bite a century ago is what helped establish the zoo as an antivenom pioneer. In 1916, a rattlesnake bit a Bronx Zoo reptile keeper, who was saved by a f