For these animal handlers, safety is paramount. They know all too well what happens if you forget to replace the "tiger out" sign on the cage when the tiger is actually in.
Quick, which animal is the biggest threat to zookeepers?
If you voted for lions or tigers, you lose. Ditto for bears. When it comes to animal handlers, elephants win hands down.
"The elephant is the most dangerous," says Dr. Keith Hinshaw, vice-president for animal health and senior veterinarian at the Philadelphia Zoo. "He's the number one offender. More animal handlers have been killed by elephants than any other animal."
Why are the lumbering pachyderms such a menace? In part it's psychology, according to Hinshaw. "It's true that an elephant never forgets," he says. "And if they don't like you, they'll wait for months if necessary, until no one is around. Then they'll do a headstand on you. Or hold you down and step on your head." Another reason elephants may be such a threat is that keepers don't venture into cages with the big cats, but entering enclosures to wash and feed elephants is still common.
Steve Clarke, an elephant handler at the Fort Worth Zoo, is sympathetic to the elephant's plight. "I've been knocked down a few times, had a few scares, but mostly when I was younger," says Clarke. "There are some aggressive elephants, and often you can see where it may go back to their upbringing, where they were mishandled in the past."
Among zookeepers who are conscious of the danger, however, "free contact" in elephant cages appears to be on the wane.
In this regard, elephant handlers may one day be as cautious as the keepers of the big cats. No matter how much keepers like felines, no keeper with his wits about him knowingly steps inside those cages. Lion and tiger attacks on keepers and vets may still occur, however, when locks and gates are accidentally left unsecured, a careless employee forgets a crucial warning, or a piece of equipment suddenly fails. As a result, animal handlers have had fractures, amputations, and infected bites. Some have even died from their run-ins with their beloved charges.
"A lot of problems arise because handlers think a cage is empty when it's not," says Hinshaw. "Maybe someone forgot to change the sign on the cage that says, 'Tiger Out.'" In 2007 at the Denver Zoo, an animal handler was mauled to death by a jaguar when she apparently failed to properly close a door separating her from the animal. "And sometimes a big cat will take a swipe at you when you're walking between cages," adds Hinshaw. "If they get an arm, they'll try to pull you inside."
Don't forget to lock
Elephants and big cats, of course, are just a few of the zoo's live-in hazards. As Hinshaw puts it, "Just about any animal that has a mouth can bite." (He singles out a favorite of the public -- North American river otters -- as "10 pounds of muscle with a bad attitude.") He himself had a close brush with mortality when someone failed to put a lock back on a small back-up cage where he was doing a TB test on the mother of a young 70-pound gorilla.
Hinshaw was balancing on a ladder when the young gorilla next door, enraged by the intrusion, ran over and pounded on the door as a threat gesture. To Hinshaw's shock, the door swung open and the furious animal charged into the cramped enclosure with him. "I tried to shut the door, but she was stronger and jumped on me," says Hinshaw. "She bit me on the back as I fell down the ladder. Luckily I had on thick coveralls; she left a ring of teeth marks on my back, but they didn't penetrate. I tried to push her away, and she tried to scratch my face. She was hitting me on the head and neck when three people managed to pull her off and throw her back behind a locked door."
Gorillas may favor pounding and biting, but injuries inflicted by other animals are as numerous as their methods of defense. Porcupines give needlesticks. Macaws scream so loudly they cause hearing damage. Anteaters have two long claws that can rip flesh. "And giraffes can decapitate a lion by kicking backwards, so imagine what they can do to you," Hinshaw says.
Animal attacks, as Hinshaw and other zoo veterinarians have seen, can result in bites, scratches, puncture wounds, bone fractures, amputations, musculoskeletal injuries, compression injuries, poisonings, infections, and blunt trauma (kicks, hits, punches, wounds from being sat on or stepped on), and death.
Perhaps it's not so surprising, then, that 61.5 percent of zoo vets report at least one major animal-related injury during their careers, with 17.8 percent requiring hospitalization, according to a report in the Journal of Zoo and Wildlife Medicine.
Veterinarians, for example, have to keep their guard up even when examining restrained or sedated animals. A heavily sedated tiger in deep REM can still bite down during dental work and put an oversized incisor through your hand, says National Zoo Director Dr. Lucy Spelman -- although she still describes her job as "the best in the world."
Even when handling an animal as small as a Siamese cat, unwary keepers may still be at risk of, say, goring. "There's an animal called a dick-dick that's about the size of a house cat," Hinshaw says. "It has a little horn about an inch long. And one ran at a zookeeper and plunged its little horn right into his kneecap."
Slipping and sliding
In fact, it's the more mundane injuries that are most common at the zoo. Repetitive strain, slips and falls, and back and other musculoskeletal injuries from lifting bales of hay and moving sedated animals or other heavy loads are most likely to put you out of commission. A full 60 percent of zoo veterinarians have suffered falls, and 60 percent have sustained back injuries, according to the Journal of Zoo and Wildlife Medicine.
"In reality, all kinds of work injuries crop up at the zoo," says Hinshaw. "The horticulture staff may have to climb trees and get bee stings and poison ivy. Gardeners are exposed to pesticides. Food service people may slip on grease and burn themselves with the deep fryer."
In addition, allergies and the minutest of organisms -- parasites, bacteria, and viruses that can be transmitted between animals and keepers who fail to use proper precautions -- can turn a zoo into a real jungle. One third of zoo veterinarians have suffered an allergic reaction to an animal or contracted an animal-transmitted disease such as ringworm or psittacosis, and 14 percent have been exposed to rabies, the zoo and wildlife journal reports. (Many animal allergies come from contact with proteins, usually those found in animal dander or urine; zoo employees who use latex gloves also run the risk of developing a latex allergy.)
Trauma from an animal attack can also result in infections -- particularly if the wounds are contaminated with saliva, feces, urine, or dirt -- or lead to tetanus, cat scratch fever, and a variety of other bacterial infections. Infections can also attack the respiratory system (such as pneumonia or tuberculosis) or develop after contact with animal blood (either from touching a bleeding animal or getting a needlestick injury).
As if that weren't enough, macaque monkeys can give their handlers herpes B if they bite or scratch them. (Most zookeepers who are bitten remain asymptomatic, but some cases have been fatal.) And at least one of the controlled substances used in zoos - an ultra-potent narcotic -- is so deadly that even one drop of it under the skin caused by mishandling a syringe could prove fatal; along with the other dangerous medicines, it's kept under lock and key.
But viruses, bee stings, and controlled substances aren't what make the news. Rather, it's the rare animal attack that cause our atavistic fear reflex to kick in, perhaps harkening back to ancient days on the savannah when we were the prey of claws, teeth, hooves, and super-size beaks that could wipe out humans in the blink of an eye.
It's all happening at the zoo
Given the high rates of attacks, allergies, and job-related disease, why does working at the zoo remain such a popular job?
"We like the physical contact and personal associations you can have with the animals," says Steve Clarke. "You have to have an interest in wanting to help animals and nature and educating the public."
Hinshaw is about to attend to a baby flamingo waiting outside with its parents. "Every job has its hazards, but ours also has its great rewards," he says. "Animal keepers love what they do, and the risks can be minimized."
Certainly that's what the directors try to do at America's largest and most professionally run zoos, which are accredited by the Association of Zoos and Aquariums (AZA), which insists on strict personnel health and safety protocols. Among the most advanced protocols in the nation are those maintained by the Philadelphia Zoo and at the Baltimore Zoo. At the latter, vets and animal handlers routinely receive vaccinations for TB and rabies, and are tested annually for parasitic diseases. Researchers at the Baltimore Zoo bank blood at a separate site to test for other zoonotic diseases as well. "It costs us thousands of dollars a year to maintain (these standards), but we feel it keeps both the animals and the people healthier," says Dr. Mary Denver, a Baltimore Zoo veterinarian.
As Hinshaw says, all risk is relative. "As far as zoo vets go, dog and cat practice has a higher risk of animal problems because most of our animals are asleep when we work on them. I'm not as brave as some vet working on a wide-awake Rottweiller."
-- David Helvarg is the author of Blue Frontier: Saving America's Living Seas, The War Against The Greens, and Rescue Warriors.
David J. Hill, M.E.M., et al. "Occupational Injuries and Illnesses Reported by Zoo Veterinarians in the United States." Journal of Zoo and Wildlife Medicine, 1997, pp. 371-384.
Zoonotic Diseases, 2nd Edition. The American Association of Zookeepers, Inc.
Stephanie R. Ostrowski. "B-virus from Pet Macaque Monkeys: An Emerging Threat in the United States?" Emerging Infectious Diseases, Vol.4, Number 1, January-March 1998.
Guy Tascano. "Dangerous Jobs." Bureau of Labor Statistics.
Denver Zoo: Zookeeper at Fault in Fatal Mauling. The Denver Channel. June 19, 2007.