WHEN SNAKES BITE, ZOO COMES TO RESCUE
Dallas collection holds impressive variety of poisonous reptiles
DALLAS—When a Texas man was bitten by an African bush viper, the Dallas Zoo was ready to strike. Along with one of the country’s most impressive collections of venomous snakes, the zoo also has one of the largest supplies of antivenom.
Most snakebites involve native species and bad judgment, jokes Bradley Lawrence, the zoo’s reptile and amphibian supervisor.
“Most of the time it’s native venomous snakes that somebody has decided to mess around with, late at night, probably because they’ve had a few too many,” he said. “Like, ‘Oh, look, there’s a snake. Let’s pick it up!’ “
Most native snakes’ antivenom is stocked in hospitals, but when someone in the Southwest, from Louisiana to California, needs an antidote for an exotic snakebite, the zoo is often called to help.
Such a call may come only once a year, but Lawrence said the calls often come about 3 a.m. and he is usually the person who answers.
The zoo will deliver at least half of its supply o of the necessary antivenom through police o or CareFlite, which carries the vials by he helicopter or plane. The hospitals that rec receive the antivenom pay to restock w whatever isn’t returned. The zoo keeps thousands of vials— about $200,000 worth—in a small refrigerator.
The most recent call for help came in January, when a man in the DallasFort Worth area was bitten by his A African bush viper, an exotic species without its own antivenom. In such cases, the zoo sends an antiv antivenom that scientific papers have shown c could work, Lawrence said.
The African bush viper is illegal to own in Dallas and Fort Worth, but “laws are always broken,” said Mark Pyle, president of the Dallas-Fort Worth Herpetological Society.
The Texas Parks and Wildlife Department sells controlled exotic snake permits for venomous snakes and five of the constrictor species for $20 for recreational owners and $60 for commercial permits. But cities often ban the possession of venomous snakes, wildlife permits specialist Megan Russell said.
But she said the number of permits issued
doesn’t reflect the number of people who own venomous snakes without following the rules.
Privacy laws prevent the health care workers who treated the man who was bitten by the bush viper from discussing the case. But typically anyone bitten by such a snake in the Dallas area is treated at Parkland Memorial Hospital—which senior toxicology fellow Dr. Nancy Onisko calls “the Snakebite Center of Excellence.”
Parkland doesn’t treat many exotic snakebites. In 2014, it treated one or two—compared with about 50 bites involving native species such as copperheads and rattlesnakes.
Copperhead bites are the most common, and they generally involve only pain and swelling.
The hospital occasionally treats rattlesnake bites, which can cause tissue death, blisters and other symptoms such as a rapid heartbeat and problems with blood clotting.
When treating a bite, doctors determine the kind of snake involved and familiarize themselves with the venom’s effects, the best antivenom to use and the risks. Some people can be allergic to antivenom, which is made by a few national suppliers. Prices for antivenom—before a hospital’s markup—range from $200 a vial for Asian snakes to $2,500 a vial for Australian species.
Therapy usually begins with four to six vials, but up to 30 vials may be needed in extreme cases.
At the Dallas Zoo’s reptile house, each cage is labeled with information about the snake and its corresponding antivenom. About 65 of the building’s 90 species of snakes are venomous, said Ruston Hartdegen, the zoo’s curator of herpetology.
Perhaps the nastiest of the lot is the inland taipan, one of the deadliest species in the world.
“One drop is plenty to probably kill everybody at the zoo today,” Lawrence said of the taipan, aptly nicknamed the “fierce snake.”