Is lab use of “model organisms,” including mice, really down by 68%?

White Coat Waste Project has more faith in defunding than in Three Rs progress;  Wayne Hsiung pushes for more “open rescue”

WASHINGTON D.C.––At a glance,  a newly published study directed by University of Bonn geneticist and evolutionary biologist Nicolas Gompel seems to suggest a drastic drop underway quietly in the background of biomedical research for more than 30 years in the use of “model organisms,”  a term including mice,  by far the most often used mammals.

Such a drop in use––if actually occurring––would be distinct from the reductions over the past 60 years in biomedical research use within the United States of species tracked and monitored under the U.S. Animal Welfare Act,  including dogs,  cats,  non-human primates,  hamsters,  rabbits,  and guinea pigs,  whose use has been replaced in large part by expanded use of non-regulated species such as mice,  rats,  birds,  and fish.

The Gompel study covers use of “model organisms” worldwide.

What’s a “model organism”?

“Model organisms” is an all-inclusive term for eight small sentient species,  such as mice,  who are both among the species most often used in scientific experiments and among those whose care and suffering is the least monitored and regulated.

Among the eight “model organisms” whose use Gompel et al studied are mice,  nematodes [worms],  fruit flies,  and yeast,  along with four species of bacteria.

None of the “model organisms” are protected by the U.S. federal Animal Welfare Act,  nor is their use monitored by any U.S. agency.  Mice,  nematodes,  and fruit flies are considered sentient and capable of suffering;  yeast and bacteria are not.

And less use of yeast could even mean that scientists are making less beer.

NAMs are not just another hangover from the Vietnam War

If indeed the drastic decline in “model organism” use has occurred that Gompel et al project,  this 30-year trend may reflect increasing acceptance of what have come to be called NAMs in scientific jargon,  short for New Approach Methodologies.

NAMs include organ-on-chip modeling,  use of tissues such as skin cells,  hair,  and sperm cells in place of entire animals,  a field called computational toxicology,  and disease modeling using artificial intelligence to predict the responses of living organisms to drugs and other chemical substances.

Both the U.S. National Institutes of Health,  directed by Jay Bhattacharya,  and the U.S. Food & Drug Administration,  under Martin Makary,  in April 2025 announced intent to reduce dependence on animal studies.

            (See Is NIH under Trump really replacing animal testing, or just axing research?)

“Menagerie of model organisms”

“Behind the research that cracked the genetic code,  uncovered the intricacies of cell division,  and unveiled the rules of inheritance was a menagerie of model organisms,”  began Science reporter Mitch Leslie,  describing the findings by Gompel et al.

“This small roster of species,”  Leslie explained,  “has featured in much of the research in biology for more than a century—including the work of more than 80% of Nobel Prize winners in physiology or medicine.”

Gompel et al,  however,  “tracked published papers over a 30-year period in 48 journals,”  Leslie recounted,  finding “a 68% decrease in the proportion of studies that depended on model organisms.  The share of fruit fly and yeast papers dropped by more than 90%.”

But did the findings actually indicate any reduction in animal use,  or animal suffering?

Data does not mean reduction in animal use

Continued Leslie,  “From these data it’s ‘not necessary to conclude that model organism use is down,'”  according to Rachel Ankeny,  introduced as “a philosopher who studies model organism research at Wageningen University & Research.

“If model organism work has done its job,”  Ankeny added,  “it should be falling away.”

That would be encouraging,  but the question remains,  did it really happen?

“Gompel and colleagues,”  wrote Leslie,   “tallied model organism papers published between 1995 and 2024 in 48 general science or biology publications, including Science, Cell, Nature, Evolution, Immunity, PLOS Biology, and The EMBO Journal.

“The number of papers on the eight species climbed over the 30-year period,  the team determined, but their overall share of the scientific literature fell dramatically because the number of papers that didn’t involve the creatures rose much faster,”  Leslie summarized.

No actual reduction in mouse use

In other words,  Gomel and colleagues did not really find that sentient model organisms are being used less in laboratories,  only that other research methods are being used more.

Further,  Leslie continued,  there was no “reduction in the number of scientists who study the organisms,  the researchers found when they analyzed conference attendance.”

Further,  mice “defied the model organism trend to some extent,”  Leslie noted.  “The number of mouse papers per year remained about the same between 2015 and 2024,  and the fraction of papers on the rodents in top journals also stayed roughly constant from 1995 to 2024.”

Gompel fretted that “model organisms are losing their original identity as the systems to discover fundamental properties of life.”

Responded Oregon State University systems toxicologist Robyn Tanguay,  who works with zebrafish,  to Leslie,  “It’s not like the models are dying out,  but maybe their visibility is decreasing.”

NAMs & drug development

The Gompel study appeared,  and was reviewed by Science,  parallel to an announcement from the Food & Drug Administration Center for Drug Evaluation & Research of “the availability of a draft guidance for industry entitled ‘General Considerations for the Use of New Approach Methodologies in Drug Development.’

“The purpose of this draft guidance,”  the Center for Drug Evaluation & Research explained in a media release,  “is to provide drug developers with a validation framework and general recommendations for using new approach methodologies (NAMs) in drug development.

“Although animal toxicity studies have proved to be a critical method to identify potential risks to human health,”  the media release said,  “finding ways to improve human relevance while reducing the use of animals by developing reliable NAMs furthers an important Center for Drug Evaluation & Research priority to move away from reliance on animal testing.”

NAMs budget is not “a victory for animals,”  says White Coat Waste Project

Animal advocacy groups mostly hail the advent of NAMs as the beginning of the end for animal studies.

Generations of animal rights advocacy have produced marked reductions in the use of dogs,  cats,  and non-human primates,  including several governmental agency policy changes away from use of dogs and cats driven by White Coat Waste Project campaigns to defund specific experiments.

Regardless of the role of NAMs in traditional Three Rs “reduction,  refinement,  and replacement” of animal use in science,  White Coat Waste senior vice president of advocacy and public policy Justin Goodman continues to see defunding animal use as the leading edge of progress.

The $150 million NAMs research commitment touted by Bhattacharya,  Goodman emailed to ANIMALS 24-7,  is not “a victory for animals,”  Goodman said,  “and it might not ever be.

“First,”  Goodman explained,  “$150 million is just 0.3% of the National Institutes of Health’s $50 billion budget,  compared to the roughly 40% historically spent on animal testing.

Scientific method means learning from failure

“Second, most research fails—whether it uses animals,  NAMs,  or anything else.

“Animal rights groups often cite the ‘replication crisis’ in animal experiments as proof the system is broken,”  Goodman mentioned.

“That’s true—but high failure rates are not unique to animal testing.  Failure is inherent to science,”  because the scientific method itself consists of learning things through trial and error.

The process of discovery is the process of identifying and eliminating hypotheses to find the explanation for something that yields a repetitively predictable result.

“Cut funding for animal tests & stop mandating them”

“Some estimates suggest that up to 90% of biomedical research,”  including non-animal-based studies as well as those relying on animal models,  “is wasteful due to poor design,  irreproducibility,  or other factors,”  Goodman continued.

“That’s why I told Dr, Bhattacharya after his confirmation that it’s a mistake to predicate ending animal testing on the success of NAMs—because most promising ideas simply don’t pan out.

“Even if 10% of NAMs succeed,”  Goodman said,  “their impact is often narrow—targeting specific pathways,  organs,  or mechanisms.  Each tool replaces only a small slice of research.

Concluded Goodman,  “Unless you cut funding for animal tests or stop mandating them,  labs have little incentive to change.”

Ridglan redoux

Also concurrent with publication of the paper by Gompel et al and the release of the Food & Drug Administration ‘s “General Considerations for the Use of New Approach Methodologies in Drug Development,”  Simple Heart blogger and Direct Action Everywhere founder Wayne Hsiung announced a “New plan to save the Ridglan dogs,”  referring to the beagles bred for biomedical research by Ridglan Farms near Blue Mounds,  Wisconsin.

Hsiung on the morning of March 15,  2026 led about three dozen activists in removing 31 beagles from Ridglan Farms,  eight of whom were recovered by law enforcement and returned to Ridglan,  while 22 remained “liberated.”

“They can’t arrest & jail us all”

Twenty-seven of the activists,  including Hsiung himself,  were arrested.

(See Ridglan Farms raid on March 15, 2026: were any beagles rescued?)

Hsiung’s “new plan” calls for “2,000 people to take action at Ridglan Farms on April 12,  2026—one person for every puppy still trapped in a cage—to create unstoppable momentum and free every dog tortured in a lab.

“There are only around 400 deputies in Dane County,”  Hsiung continued,  “including those serving in jails and not on patrol,  and 800 spaces for inmates in Dane County jails.

“If we can mobilize 2,000 rescuers,  they can’t arrest and jail us all.  We’ll carry every last one of the dogs out of Ridglan into loving homes.

“In the last five days,”  Hsiung claimed on March 20,  2026,  “nearly 30,000 people have signed up to take action to the next level.”

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