BLOG: The Hidden Suffering of Laboratory Mice and Rats

July 31, 2023

By Greta Fiedler, Legal Intern

“But the terrible silence and emptiness seemed to symbolize her future—she felt as though the house, the street, the world were all empty, and she alone left sentient in a lifeless universe” – Edith Wharton, The House of Mirth

When I was eight years old my dad bought me a Chinese Dwarf Hamster from PetSmart. I named her Penelope after a character in the Japanese magna and storybook series, Hamtaro, which is based on a friend group of hamsters who each escape their respective cages during the day and take part in many adventures together, including hanging out in their clubhouse which they built in the roots of a tree. I fawned over Penelope and adored watching her construct her nests, tire herself on her wheel, and aggressively chew the bars of her cage, which was no larger in square feet than a shoe box. She spent hours a day hacking at the bars that imprisoned her, and I justified it by telling myself it was because her teeth were growing so quickly, and she needed to keep them trimmed. I failed to make the connection—even the morning before school when Penelope finally managed to escape through a side door of her cage—that no matter how much I loved playing with Penelope, like putting her in her pink plastic ball and letting her run around the house, that she was desperately trying to escape me. I burst into tears the morning I found Penelope stuck in the sticky trap near the garage door. Due to my inconsolable nature, my dad freed her with a bottle of baby oil. Unfortunately for Penelope, this meant a transfer to a slightly larger cage with glass walls, making it impossible for her to climb out next time.

Rodents played a large part in my childhood. Even before Penelope, when I was five and my mother was hospitalized with a mysterious illness that left her paralyzed, my dad bought my sister and me a pair of gerbils, Ying and Fong. As an adult, I now realize that the gerbils served as a distraction to give us something to talk and think about other than our dying mother. But even more so, the distraction worked. I remember Ying and Fong almost as vividly as I remember my mother. Fong was much more gluttonous than Ying, who was frail and shy; I still smile at the fact that we always found Fong sleeping on top of Ying. This colors the many ways us humans can feel connections with all sorts of animals, even those as small and societally invisible as a gerbil. And the reason why we can form such connections with rodents—such as Penelope, Ying, Fong, or the countless rats and mice used for research—is because they are not that different than any other animal that humans form close bonds with. They have personalities, express affection, initiate relationships, and are empathetic in nature.

The dark reality to my reminiscences about Penelope, Ying, and Fong, is that these memories were formed at the expense of imprisoning an individual sentient being—a being who, if given the choice, would have left my companionship to burrow in and roam the outside world (or perhaps form a clubhouse with their friends inside a tree). The even darker reality is that Ying, Fong, and Penelope were all bred into existence for the purpose of being trapped in a tiny cage by some skittish little girl whose form of play was their form of torture. And while I felt a deep bond with my rodent pets, like how many people have felt with a cat or dog, the standard of treatment rodents experience is much different than the moral standard most people hold for cats and dogs. This is especially evident when examining the life of the millions of rats and mice intentionally bred and tortured in American laboratories in the name of science. 

One recent study estimates that as many as 111.5 million rats and mice are bred and trapped in American laboratories every year. For perspective, this is equivalent to about 3x the population of Canada. This is a substantial amount of little sentient beings who spend their lives in shoe box sized plastic containers injected with diseases like HIV and cancer, and/or are electroshocked, toxified to death in toxicology studies, drowned, burned, amputated, and experience feelings of terror, anxiety, depression, and helplessness throughout the entire process.

While the level of suffering endured by mice and rats in research is often obscured by bland and sterile written descriptions in research records, it takes little imagination to fathom what these individuals endure. In records recently obtained by Animal Partisan, a researcher at George Mason University (“GMU”) in Virginia recently proposed a study to determine if young blood plasma can restore behavioral functioning after a repetitive mild traumatic brain injury (rmTBI). The proposed research involved breeding over 900 mice in a lab. Some of these mice would be designated as donor mice, who are bled to death at 8 to 10 weeks of age. The mice who are not breeder mice nor blood donors will undergo brain injury.

Let’s name one of these mice, Harry. When Harry reaches 8-weeks-old, a researcher will restrain him, put him under anesthetic, and position his head directly in the path of a device that will give him a concussion. When Harry awakes from the anesthetic, the device strikes him in the head, the platform falls, and he tumbles to the ground. A researcher will then sit and observe Harry, measuring how long it takes for him to stand up and walk again. If Harry is deemed too injured, the researcher will kill him. If he survives, Harry is forced to endure a concussion four times with 48 hours in between each event. He also undergoes a blood transfusion or saline injection every 72 hours a total of 16 times. Amid these brain injuries and injections, Harry must perform various activities to measure his recovery like swimming until he locates a platform, completing mazes, and walking after a researcher coats his feet in paint. Then once he is no longer useful, Harry is killed. 

In addition to such overt acts of cruelty disguised as research, mice and rats are also subjected to more passive neglect. Animal Partisan obtained five letters (Letter 1, Letter 2, Letter 3, Letter 4, Letter 5) of noncompliance from Virginia Commonwealth University (“VCU”) sent to the Office of Laboratory Animal Welfare (“OLAW”), an entity that oversees the “care” and use of research animals in public and private institutions. These letters admitted that VCU had failed to provide proper care to mice during experimentation between December 2021 and October 2022. The letters depict serious deviations from the Guide for the Care and Use of Laboratory Animals at Virginia Commonwealth University, including multiple occasions of mice starving to death because the staff forgot to provide food. VCU’s apathetic caretakers also caused severe dehydration and death to mice due to a jammed water bottle, and they even left a cage of neonatal mice on a supply shelf and almost forced them through a scalding hot cage wash. After each instance VCU imposed more rigid procedures and training to the caretakers, but the heightened procedures did not stop the instances of noncompliance.  This reveals how active and passive abuse are linked. It is a paradox to expect researchers who are actively abusing animals in the name of science to then be devoted caretakers in the animals’ downtime. The only way to ensure that animals are treated with dignity and respect is to not experiment on them at all.

The reality is that mice and rats are sentient and emotionally complex creatures. Mice are empathetic individuals who react more strongly to negative experiences when other mice are unwell. In addition to empathy, mice can form deep relationships with other mice, like expressing romantic interest through love songs. Rats also experience a wide array of emotions like laughing when tickled. They are altruistic and will forego sweets to jailbreak their friends then share the treats with one another after the fact. Both considerate and intelligent, rats are proven to have outperformed human beings in information integration tasks. Yet, members of the scientific community, like at GMU and VCU, subject rodents to a short life of pacing around a tiny cage, painful and tortuous injuries, and almost every form of abuse imaginable.

To make matters worse, the experiments themselves are not particularly beneficial for human beings. Due to the conditions mice and rats are living in during experimentation, their stress reactions add variables that are not accounted for. Dr. Garet Lahvis, an Associate Professor of Behavioral Neuroscience at Oregon Health and Science University, says, the “myopic focus strictly on animals living inside impoverished cage environments” means that “we are studying biological processes that likely occur only inside a cage.” Lahvis asserts the solution is to create lab environments that mimic the natural world. Yet, he fails to recognize the scientific irrelevance of experimenting on animals in the first place. In an article published by Cambridge University, Aysha Akhtar argues that there are not only environmental stressors that make data from animal testing irrelevant, but there are differences in biology and genetics that are misleading when the results are translated to humans. In fact, promising results found in rodents often creates false security for humans. For example, some experiments that were auspicious for rodents resulted in injury to human beings, like increasing cardiovascular disease risk, brain swelling, and in one example, systemic organ failure. More often, positive results in rodents are found to have no effect in the human body. There is a collective harm that results from animal experiments for both human animals and non-human animals. This is especially evident because there are alternatives to animal testing that are more accurate. For example, the National Institutes of Health (“NIH”) has committed to further developing non-animal model alternative methods, such as utilizing cells in test tubes, 3D tissue culture, computational models, stem cell research, noninvasive diagnostic imagining, and volunteer based clinical research. While alternative methods exist, the NIH still spends $14.5 billion every year on animal research.  Akhtar concludes her article questioning the “ethical justifiability of animal experiments” that “deprive humans of resources, opportunity, hope, and even their lives by seeking answers in what may be the wrong place.” A better use of the funds could be spent developing more accurate, human based technologies. And while these human based alternatives would benefit humans; the true motive should be to end systemic abuse of sentient beings.

The reason for humans’ exploitation of rodents is not because they are animals with less capabilities, emotional breadth, and intelligence, but it is due to the vulnerability that is packaged with their small size and low-cost care. Yet this vulnerability does not mean that rats and mice suffer less. Sentience not only means the ability to suffer, but it also indicates the ability to experience emotions opposite of suffering, like friendship, love, and play. Experimenting on rodents not only inflicts perpetual pain, but it also deprives them of the experiences in life that are meaningful; it is this crime that I find most heavy. What is the point of one’s sentience if one is born and dies in sterile emptiness?

I think about little Penelope and how her life was spent trapped alone in a tiny cage. The first time I put her in her pink plastic ball, she sprinted as fast as she could around the house in effort to escape it. But after a couple of afternoons in the ball, she eventually realized the bubble enclosure would always come with her. One day she stopped running all together; she sniffed around the ball, located the lid, and began chewing at the locks. The immensity of the world awaited her, yet her world was the size of a plastic sphere. She, and millions of others like her, lived their entire life in desperation of something more—left sentient in a lifeless universe.

Greta Fiedler is a 3L at the University of Oklahoma College of Law who aspires to advocate for animals both inside and outside of the legal system.