Unnecessary Suffering: Captive Primate Experiments

Mike Ryan, November 29, 2018

A summary of primate experimentation

  • As of 2017, roughly 70,000 primates were used in experiments that took place across 190 entities (both private and public) spanning 42 U.S. states.

  • Nearly 29,000 of these primates were used in experiments that are referred to as Category C or D, meaning pain and distress are involved, often with no pain relief of any kind. Experimenters often claim that euthanasia at the end of the experiment constitutes “pain relief”.

  • In 2015, the U.S. banned experiments on chimpanzees, with the Director of National Institutes Health (NIH) stating it was the “right thing to do.”

  • It is unclear why this moral imperative doesn’t extend beyond chimpanzees to other primates, who share our capacity for sadness, pain, and distress.

  • Most nonhuman primate experiment work is related to infectious diseases; psychology; reproductive biology; regenerative medicine; aging; and neuroscience research.

Louisiana, Massachusetts, and Wisconsin are the worst-offending locations

Within the 42 states in which nonhuman primates are used in medical experiments, the largest numbers are seen in Louisiana, Massachusetts, and Wisconsin. Taken together, these three states use more than one third of all primates in U.S. facilities. Louisiana and Wisconsin are each home to a National Primate Research Center (NPRC), and house 5,228 and 8,412 primates, respectively. Massachusetts made the list because it’s home to Charles River, the largest animal breeding and testing facility in the U.S. private sector.

Experimenters procure primates by importing them from other countries or obtaining them from taxpayer-funded domestic breeders

Importation: Most (over 90%) of all imported primates are crab-eating macaques. Most come from China or Mauritius. Since 2012, over 90% of the nonhuman primates imported into the U.S. have been crab-eating macaques; about 23,000 of these arrive in the U.S. every year.

  • Airlines Don’t Want This Cargo Business: As of 2018, all but one of the commercial airlines refuse to ship animals to be harmed in medical tests. Air France is the only holdout. As of this writing, a group that profits from primate experimentation has asked the U.S. Department of Transportation to force airlines to ship primates. We’re defending the airlines ‘right to refuse’ to ship primates, and applaud their stance against participating in this cruelty. It’s common sense for these airlines to refuse to ship animals in these situations. After all, shipping these animals puts passengers and airline personnel at risk for communicable zoonotic diseases.

Domestic breeding: Several breeding colonies exist in the U.S., and many receive direct financial support from the NIH. The network of federally-funded NPRCs is a leading source of domestically-bred nonhuman primates used in experiments.

Certain primates suffer most

Rhesus Macaques, Crab-Eating Macaques, Baboons, and Marmosets are among the most used primates in research.

There are 190-230 species of nonhuman primates in existence, but only a small handful of species have the misfortune of being singled out to suffer in medical experiments. Here’s a look at which are most abused:

Rhesus Macaques: Over 65% of the time, experimenters use rhesus macaques. Even though our (human) genome and theirs diverged 25 million years ago, our DNA is 93% similar to that of rhesus macaques. As such, it’s no surprise that they’ve repeatedly demonstrated self-awareness (recognizing themselves in mirrors, for starters), and that their minds are impressive: They count, use tools, understand basic rules, demonstrate same/different judgement ability, and overall show complex cognitive abilities. As noted in 1993 by Carl Sagan and Ann Druyan in Shadows of Forgotten Ancestors, a series of cruel experiments done at Northwestern University in 1964 revealed that rhesus macaques would rather starve than hurt one another.

Crab-Eating Macaques: The second most commonly used species is the cynomolgus macaque, which is used roughly 15% of the time. Interestingly, crabs aren’t the mainstay of their diets, but the name stuck. The most famous abuse of crab-eating macaques was in the Silver Spring monkey case in the 1980s, an exposure of an NIH-funded experiment that was so vile that police raided the facility. A mix of Congress and the courts ensured these experiments weren’t resumed, although countless others like them continue to this day.

Baboons: Baboons are used for experiments about 5% of the time. They are playful and intelligent, and their pastimes sometimes overlap with our own. For example, baboons in Nigeria have been observed swimming and diving seemingly for their own amusement, as it wasn’t related to getting food.

Marmosets: A kind of marmoset called the “Common Marmoset” is used about 3% of the time. Like all primates (including humans), marmosets are highly intelligent and emotional creatures, with complex social lives. They’re extremely vocal with one another, using high-pitched calls that often sound like birds. Interestingly, mature marmosets don’t often interrupt one another in conversation and instead take turns during vocal exchanges. Some of their family relations remind us of our own, too. For example, mature daughters are generally subordinate to their mothers, which experts compare to the relationships between human sons and fathers. There appears to be a generally increasing trend in use of nonhuman primates since FY13, driven largely by increasing use of rhesus and cynomolgus macaques.

Public opinion shows Americans oppose primate testing

Your tax dollars are paying for methods you’ll find abhorrent.

A poll conducted by NEAVS of American adults in 2018 revealed that 70% of Americans opposed using primates in medical experiments. In addition, Gallup polling has shown a consistent year-on-year increase in opposition to animal experiments generally.

In 2001, 65% of Americans said medical testing on animals was morally acceptable. By 2018, that number fell to 54%. If trends hold, that means that by next year an additional 9 million fewer Americans will find medical testing on animals acceptable.

At this rate of change, by 2021, according to Gallup, in just over two years, a majority of Americans will see medical testing on animals as morally unacceptable. Gallup’s polling is the most conservative on this topic; other polls including those by Pew Research indicate that the number of Americans opposed to animal experiments is closer to 60% as of 2018.

Unfulfilled obligation: NIH-funded primate experiments are increasing

NIH reassures Members of Congress that they’re still trying to ‘reduce,’ which is required by the Animal Welfare Act, so why aren’t they?

In 1959, zoologist Bill Russell and microbiologist R.L. Burch first proposed the concept of the Three Rs (Replacement, Reduction, and Refinement) as guiding principles for the use of animals in experiments.

Replace means use non-animal methods instead of animals. Reduce means to use fewer animals over time. Refine means to adjust animal experiments to make them less painful and distressing.

Over the past 40 years, the Three Rs have become widely accepted ethical principles in medical experimentation and elsewhere, and are now embedded in the conduct of animal-based science in many countries, including the U.S.

NIH takes direction (and funding) from the U.S. Congress, which incorporated the long-established principle of the Three Rs directly into the Animal Welfare Act. When Congress made the Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), that legislation establishes the Three Rs as core to what ICCVAMs are supposed to be working toward.

Put simply, the Three Rs are federal policy for biomedical research and toxicity testing. The purpose of this was for NIH to, over time, reduce the number of animals used in medical experiments.

The NIH has repeatedly reassured Members of Congress that they are working to reduce the number of nonhuman primates in medical experiments and are funding alternatives to do so. However, an analysis of USDA data reveals that the numbers of primates suffering in experiments is rising and is now at an all-time high, as initially noted by NEAVS, and later reported by Science Magazine.

There’s a better way: non-animal methods

Thanks to Congress (and many at NIH), alternatives that don’t require primates can be used instead.  

Thanks to Congress funding the development of tools that can replace the use of animals in medical testing, researchers today have no shortage of great options that render the use of animals unnecessary.

Examples include high-powered computer models that realistically simulate the human body and its component systems and organs, and their reactions to medicines; advanced microscopic techniques for imaging and analysing human cell functions in health and disease; and high-technology, safe imaging of the human brain to understand neurological disorders. Click here for a sampling of the leading alternatives.

Meet our advisors

In 2018, we assembled an all-star team of credentialed experts in the field of animal research and primate experiments. NEAVS’ Primate Testing Advisory Committee (PTAC) is being chaired by John Gluck, a former primate scientist who authored the compelling and groundbreaking 2016 book Voracious Science and Vulnerable Animals.

The Committee includes top minds in animal welfare and academica, including Prof. David Morton, Dr. Sushila Maharjan, Dr. Martin L. Stephens, and Prof. Stacy Lopresti-Goodman. Click here to learn more about their work and backgrounds.