06/06/2026
While mice and rats make up about 95% of research animals, a variety of other species are also used, including rabbits for eye and skin irritation testing, monkeys in drug toxicity studies, dogs (often beagles) and cats in cardiac, cancer, and neurological research, and even some farm animals.
There are modern alternatives to animal testing, such as organ-on-a-chip technology and computer modeling. While promising, they still can't fully predict complex biological responses or unexpected side effects like rashes, organ damage, or neurological changes.
Interestingly, although the FDA no longer requires animal data for every drug approval, it still strongly favors animal safety studies before human clinical trials. Scientific journals and research funding systems also tend to show an "animal methods bias," often requiring animal data to support findings from cell-based or computer models.
For that reason, animal testing is unlikely to disappear entirely. However, animal welfare standards have evolved significantly. The Animal Welfare Act (AWA) regulates the daily care of research dogs and cats, including housing, socialization, exercise, and pain management.
One of the biggest changes has been what happens after a study ends. Historically, healthy research animals were routinely euthanized. Animal advocacy groups pushed for reform through what became known as the Beagle Freedom Bill, formally called the Research Animal Retirement Act.
Minnesota became the first state to pass such a law in 2014, requiring eligible research dogs and cats to be offered for adoption rather than automatically euthanized. New York and California followed in 2016, with Illinois, Nevada, and many others joining afterward. Today, more than 15 states have adopted similar laws.
The result has been a meaningful shift in industry practice: for healthy, behaviorally suitable animals, adoption and retirement are increasingly becoming the default outcome instead of euthanasia.
