The confessions of a reluctant vivisector.

The stolen dog that changed American science.
June 5 2009 7:19 AM

Me and My Monkey

The confessions of a reluctant vivisector.

Daniel Engber Daniel Engber

Daniel Engber is a columnist for Slate

My research monkey had a pink face, dark eyes, sandy fur, and a 2-inch titanium rod screwed into the top of his skull. His name was Clayton.

It's customary to name research macaques in alphabetical order according to when they arrived at the lab. Clayton showed up after Axel and Bongo and ahead of Duper, Einstein, and Freud—but whatever institutional seniority he had meant little in the monkey room. Clayton, a juvenile, was skittish and shy, submissive as a rule, and generally afraid to leave his cage. When I'd finally manage to coax him out, he would leap straight into the "monkey chair," preferring enclosure in a small, plastic box to the thought of ambling across the laboratory floor.

Though he hardly needed it, Clayton was leashed even for these short trips from cage to chair. I'd hook a chain to his collar and slide it through a loop at the end of a 3-foot pole so he couldn't get close enough to bite or scratch. Macaques can harbor the deadly herpes B virus, and it's generally forbidden to approach one that's unrestrained and un-anaesthetized. Though Clayton and I spent hours together every day, I never so much as touched his fur during an experimental session. If he came to recognize me—and I believe he did—it was despite the surgical mask, goggles, hair net, and other safety accoutrements of any visit to the monkey room.

The monkey chair wasn't much bigger than the animals themselves, and Clayton's head poked out through sliding panels at the top. I'd roll him in front of a computer monitor and fasten his protruding metal post to an external frame. With his skull fixed in place, only his eyes could move to follow the targets that zipped across the screen. (By tracking the direction of Clayton's gaze, I'd hoped to learn something about how smooth pursuit eye movements are controlled in the brain.) His eyes would follow me, though, as I loaded up the software and filled his juice dispenser; sometimes I'd place a jelly bean or a raisin delicately on the edge of his mouth, which he'd gobble up before flashing his gums in the deferential gesture of silent bared teeth. I talked to Clayton, too, trying to keep him entertained. But every once in a while he'd show his impatience with a gesture that was disturbingly human: I remember the day he crossed his legs on the shelf of the chair and started strumming his fingernails against the wall.

The one time I held Clayton in my arms, he was asleep and swaddled in a blanket. He'd just undergone a minor surgery, probably to repair a broken eye coil. (Most of the monkeys in the lab had a thin wire implanted under one eyelid that could be used to track their eye movements.) As a junior graduate student, I wasn't allowed to do more than observe the procedure, but when it was done, one of the postdocs lifted Clayton off the table and beckoned me over. I was to carry him back to the monkey room and deposit him gently into a cage before the anesthesia wore off.

For the first time, I felt the shape of his body—the outline of his little shoulders and spindly legs. For weeks we'd interacted across bars and through thick plastic; now I had him cradled him against my chest, his eyes closed and his head tucked into the crook of my arm. He was about the size and weight of a newborn baby; with the blanket wrapped around him, only his pink face was showing, and his eyelids fluttered as I carried him down the hall.

I rocked Clayton back and forth as we made our way to the monkey room. The rest of the animals were stored in interlocking cages, stacked two high on either side; a television in the corner was showing The Lion King on an endless loop.   Axel, Bongo, and the other macaques watched as I squatted next to an open enclosure, with the bundle now nestled in my lap. I pulled one end of the blanket and began slowly to unwrap it. First once around and then again—the monkey was stirring now, his head rolling from side to side—and then the blanket was open, laid across my thighs, and there was Clayton's naked body in full view. His chest wasn't soft and pink like a baby's but tan and rugged. He had a tattoo across his abdomen of letters and numbers like the ones painted on houses in the aftermath of Katrina. And further down, nestled amid the light fur of his thighs, lay his penis—hardly the smooth, unformed genitalia of a baby but something like that of a fully grown man, shrunken down to the size of a crayon and adorned with a pair of swollen, red testicles.

A quiver went through Clayton's whole body as I took in this sight, and then a stream of liquid erupted from his groin, gradually building like a fountain that's just been switched on. An arc of urine splashed against my shoulder—and suddenly the monkey room was bedlam. Macaques began to throw themselves against the walls in a cacophony of shrieks and crashes. One animal in the upper tier started doing back flips; his neighbor stepped toward the front of his cage, turned in my direction, and started urinating, too.

I placed Clayton's small body into his cage, locked the door, and retreated to the safety of the hallway. The postdoc who had assigned me this task smiled as I peeled off my wet lab gown and T-shirt. "Don't worry," he said, as if it happened all the time.


Just as zookeepers rarely share the names of their animals with the public, so are laboratory monkeys left anonymous in the science literature. If I'd had the opportunity to publish the results of my work with Clayton, we would have called him Monkey C, in accordance with journal etiquette; other mammals, like mice, rats, and kittens, are almost never identified, even in code.

That hasn't always been the case. Ivan Pavlov called his surgical dogs by name in published lectures. Among his most successful subjects was a collie-setter mutt named Druzhok, "Little Friend." The anti-vivisectionist movement was much stronger in the United States than it was in Russia, though, and American physiologists were soon hiding the more sentimental details of their work from the public. In 1914, the chair of the Council on the Defense of Medical Research, Walter Cannon, warned journal editors to excise from their manuscripts any "expressions which are likely to be misunderstood" or turned against them by animal activists. Historian Susan Lederer has traced the expansion of this policy over 25 years at the nation's top biomedical research journal. Starting in the 1920s, she writes, a slew of technical jargon was systematically inserted into the pages of the Journal of Experimental Medicine. The word starving was replaced by fasting, bleeding by hemorrhaging, poison by toxicant; full-body photographs of lab animals were removed, and the pronoun it was subbed in for any use of he or she to describe them. Authors who referred to their animals by given names were instructed to use a string of letters and numbers instead.

That doublespeak (by now having become a matter of habit) obscures some of the incidental cruelties of animal research. But it hides just as well the attention and care that are essential to working in the lab. An experimental macaque costs about $8,000 and may require months or years of training before it can start producing useful data. That is to say, its continued health is of extraordinary value both to the professor who paid for it and to the graduate student whose dreams of a thesis depend on its well-being. It was my job to nurture Clayton so he would perform in my experiments as best he could. Given the constraints of the lab—a cage, a chair, a metal head post—I wanted him to be as happy as a monkey could be.

Outright negligence might have affected the quality of my data, as an animal in distress is likely to deliver skewed results. That idea, so obvious in retrospect, dawned on physiologists only near the turn of the 20th century, according to historian Otniel Dror. Researchers began to notice how fear or anxiety could be expressed as physiological phenomena—changes in blood sugar, for example, or digestive function. A fearful rabbit might "blush," wrote one scientist, and yield false measurements of blood pressure. While journal editors of the 1920s worked to strip emotional phrases from the scientific literature, scientists learned how to control emotion in the lab. Walter Cannon, whose letter in 1914 inaugurated the era of science-journal jargon, remarked that he could alter the gastric motility of a cat by "reassuringly" stroking her fur.

I've also experimented on cats—kittens, really—by probing their exposed brains with an electrode to see where tiny shocks might palpitate their feet. (We were studying neuroplasticity and how behavioral training affected the development of the motor map.) I spent time with the animals every day, teaching them to grab morsels of meat from a plastic container with their little paws. Like Walter Cannon, I stroked their bellies, too, and scratched under their chins. But there's no mention of those affections in the published results of the study. (Kittens "were trained to reach through the aperture to grasp the beef from a narrow cylindrical food well (3.2 cm inside diameter; 5 cm deep) using their preferred limb only," we wrote.) Nor did we mention that the animals—some as young as 3 months old—were euthanized at the end of each "intracortical microstimulation" experiment.

It's easy to see why we used this furtive language. Any sentimentality over the cats would have suggested a lack of scientific rigor, and a frank description of the killings would only invite anger from animal rights groups—and alienate the taxpayers who paid for the study (and my graduate student stipend). But it seems to me the pressure to keep the laboratory door shut comes from both sides. The public acceptance of animal research, and the biomedical breakthroughs it engenders, has always come with the understanding that no one will divulge too many of the gory details—we put up with animal sacrifice only so long as we don't have to think about it.  


On Sept. 11, 1981, police officers in Montgomery County raided the two-story Institute for Biological Research in Silver Spring, Md., and found there a gruesome, filthy holding room for experimental macaques "who were in such physical and mental stress that they appeared to have bitten off their fingers and arms, or whose cages were locked together so that they injured each other." With the help of a young animal rights activist named Alex Pacheco, the officers seized 17 of the animals, and the lab's director, Edward Taub, was charged under state law with more than a dozen counts of animal cruelty.

Photograph taken by Alex Pacheco at the Institute for Biological Research in Silver Spring, Maryland.
Photograph taken by Alex Pacheco at the Institute for Biological Research in Silver Spring, Md.

Taub's trial began in October 1981, and as happens in nearly every case of alleged laboratory animal abuse, the ugliness of invasive research became a defense in itself. Should the condition of Taub's monkeys have been taken as evidence of abuse on its own terms or in the context of how research monkeys were treated everywhere else? Expert witnesses debated every detail of the case along these lines, from the question of how filthy a monkey lab might reasonably become to whether it made sense to bandage the wound of a deafferented animal. Taub was found guilty on six counts, but five of them were overturned in a second trial the following year; he was acquitted of the sixth in 1983.

The plight of the monkeys had in the mean time generated enormous publicity for Pacheco and his fledgling advocacy group, People for the Ethical Treatment of Animals.   The photographs he'd taken in Taub's lab became the iconic images of an invigorated anti-vivisectionist movement—in particular, a shot of a macaque with its hands and feet taped to a metal frame and its arms stretched Christ-like. (At his trial, Taub accused PETA of staging some photos.) In 1984, PETA scored another publicity coup, releasing video footage stolen from the University of Pennsylvania by the Animal Liberation Front. That tape showed researchers at a head injury clinic joking around as they performed violent whiplash experiments on helmeted baboons. The uproar over the abuse in Silver Spring and Philadelphia pushed lawmakers to strengthen federal protections for laboratory animals. Like Pepper 20 years earlier, PETA's monkeys and baboons helped break a stalemate in Washington between animal welfare groups and the research establishment.

For years, a bioethicist named Bernie Rollin had been arguing that the Animal Welfare Act needed to be rebuilt with a new philosophy. In Rollin's view, the existing regulations had done little to make scientists aware of their animals' suffering. He'd testified in Congress that physiologists had not even bothered to study animal pain in a systematic way, since its existence could not readily be tested or verified in the lab. Researchers might use paralytic agents (sometimes called "chemical restraints") to prevent an animal from thrashing around during an experiment, he said, but they often neglected the use of painkillers altogether. This ideology even extended to human infants, whose subjective experience was similarly mysterious. Doctors sometimes assumed that babies were insensitive to pain and, up through the early 1980s, deprived them of analgesia during surgery.

With PETA's help, Rollin and the animal welfare groups were finally able to win their case—and the passage of a series of amendments to the Animal Welfare Act in 1985 under the stewardship of Bob Dole.   The new law required that all covered animals be given painkillers before and after surgery and that no animal be used in more than one "major operative experiment." It also mandated the creation of an institutional committee (including at least one veterinarian) wherever lab animals were used. The self-policing committees were to review experimental protocols, inspect research facilities, and evaluate whether sufficient effort had been made to reduce animal suffering.

Rollin wanted more than bureaucratic airlocks, though. He'd tried to imbue the law with a new philosophy. The amendments he helped to write introduced the idea of "performance standards" for laboratory animal care, as opposed to the "engineering standards" of old. Where the USDA's Dale Schwindaman once struggled to determine the minimum cage dimensions for dogs, cats, and hamsters—"to play God to the animals," in the words of his boss—now there was a movement to abandon recipes and regulations in favor of more ambiguous endpoints. Government inspectors would spend less time unfurling their tape measures and more time adjudicating the spirit of animal welfare: Are the laboratory dogs getting enough exercise? Are the monkeys in a state of "psychological well-being?"

That distinction, between engineering standards and performance standards, has become a source of contentious debate among animal protectionists and research advocates. (Performance standards seem poised to become even further established in an upcoming revision of the official NIH Guide for the Care and Use of Laboratory Animals.) The institutions argue that more flexible definitions are better for the animals, since they allow for quicker improvements to laboratory practice. (Under performance standards, for example, monkeys might be housed in pairs or they might not, depending on their personalities and predilection for fighting.) Welfare advocates argue that wishy-washy requirements leave too much power in the hands of on-site experts, who draw their salaries from the institutions they oversee. Christine Stevens, the mother of the original Animal Welfare Act and the woman who first brought Pepper's story to Washington in 1965, worried that performance standards "gave it all back to the researchers and said, 'Here, do what you want.' "

"I'm not a 'law' type of guy," Rollin says now. "I'm a Harley rider. I was the last guy to want to play cops-and-robbers with scientists." Instead of handing out a new set of rules for researchers to follow, he'd hoped to make them work out the ethical issues for themselves.


I returned to the monkey room one morning in March, in a yellow lab gown with paper booties over my sneakers. I'd e-mailed my former mentor two days before, to tell him I was writing about animal research for Slate and to find out what became of the project we'd started in his lab eight years ago. Had someone finished the experiment? Were the remains of monkey C buried in some academic journal with my data on the headstone? In a few hours, I had his reply: "Clayton is still around."

The primate quarters were arranged exactly as I remembered—two rows of metal boxes along the walls, two tiers on each side. A pair of adult monkeys idled near the front of their cages on the right, just inside the door: One looked haggard, with circles of dry, red skin around his eyes and his tongue lolling from the corner of his mouth; the other was more alert, eyeing me from the front of his cage with his hands folded across his belly. If there hadn't been labels the size of index cards on the front of their cages, I might not have recognized Duper and Clayton at all.

Their enclosures looked smaller than before—cramped, even—and for a moment I considered the possibility that the recession had taken its toll on the animals. Of course, it was that the animals had grown bigger: Clayton had doubled in size—the little monkey who once felt like an infant in my arms was now a slouching beast with round shoulders and thick legs. His catarrhine muzzle was more prominent than before, and there was a new mound of pink dental cement on the front of his cranium, topped by a small, plastic screw cap. Beneath it was a patch of his brain, exposed for recording electrodes. I found myself gazing dumbstruck at his queer, time-worn face.

If Clayton remembered me, it wasn't with fondness: He rose to all fours as I approached and grunted at me with his lips parted—an aggressive, open-mouth threat. There was little evidence of the adolescent who had cowered in the back of his cage eight years ago. As an adult, Clayton lingered near the bars, scowling. (I discovered later that he'd been separated from his old cage-mate Duper for fighting.)

But the constancies of his daily life were more striking than these other developments. In all the time I'd been gone, Clayton had lived in the same room, on the same feeding schedule, and with many of the same neighbors. Since we'd last seen each other, I'd moved across the country twice, quit graduate school, and become a journalist. Scientists had published more than 10,000 research papers using macaque models, and a team at the Baylor College of Medicine sequenced the entire genome of the rhesus monkey. For Clayton, though, nothing has changed. Every day or two, he's carted off to a room painted all in black, and his head is fixed in place by the post that still protrudes from his skull. He sits there as always, staring at targets on a computer screen. When he moves his eyes the way he's supposed to, he gets a droplet of Tang as a reward.

It occurred to me that Pepper had been lucky. She'd spent her life roaming an 82-acre farm in Slatington, Pa., with a mate, Fred. (They even had a litter of puppies.) Her time at Montefiore Hospital in the summer of 1965 would last all of one day: After a single night spent locked in the rooftop kennel, she was brought downstairs, anesthetized, and killed.

Clayton was born in a breeding center; he grew up in metal boxes and spent his adolescence with a hole in his head and a coil around his eye. In 10 or 15 years of life, he suffered through multiple surgeries and infections and endless hours of restraint in a plastic chair. And for what? Pepper's death, at least, contributed to the development of the cardiac pacemaker—a revolutionary medical device that would prolong millions of lives. Every hour of Clayton's existence has been spent, and will continue to be spent, in the service of basic science.

"Yep, he's still going strong," my former mentor said when I returned from the monkey room. We stood outside a recording chamber, where another animal now sat in front of the monitor. Some people might not like the idea of a monkey working so long, he continued; they say it's better to use each lab animal for one experiment only or a series of related ones … but all the experiments in a given lab are at least somewhat related. "You could easily argue," he added, that the resources necessary to buy and train a new monkey would be a net minus for animal welfare. Why should we euthanize Clayton and start over? Isn't it better for science, and more humane, to use just one animal?

That sort of moral calculus had driven me away from animal research. (I quit in 2003 after a grisly series of experiments involving a suction tube, a scalpel, and the exposed brains of a half-dozen small birds.) Does the cumulative suffering of one animal over 10 years amount to more than the summed misery of several others, used only briefly? Are we trying to reduce the total amount of pain inflicted on animals or the total number of animals killed? Now it seems to me we've grown ever more removed from these sorts of questions.

The development of animal protections has surely reduced suffering in the laboratory. Yet our safeguards have also served to quarantine the ethical debate. The protocols for painful experiments are approved by institutional committees, and the welfare of lab animals has become a topic for obscure scientific measurements. Few outside science get to see what happens inside the laboratory or consider its costs and benefits. (My recent visit with Clayton was itself unusual; primate labs are rarely so welcoming to members of the press.  

Pepper brought us through the laboratory door 40 years ago and generated enough public engagement to pass the Animal Welfare Act. Someone's pet—a member of the family—had gotten lost in the enormous enterprise of biomedicine, and we all went in after her. But scientists today no longer need to pluck stray dogs from country roads. Today's lab animals are professionals—life-long civil servants like Clayton, toiling away in the back rooms of a public institution; or else they're disposable commodities, like the millions of rats and mice that ship out from breeding centers every year. Theirs is a closed ecosystem of universities, hospitals, and breeders—a world behind doors with electronic locks.

Will anyone bother to look inside?