The Bridge to Animal-Free Science

Every scientist who works with animals is excited for the day there is a true alternative. Animal research is ethically sensitive for everyone involved, and the primary goal is always to replace, reduce, and refine the use of animals. This work remains relevant to many projects across Canada and around the world because some biological questions still require whole living systems. Scientists also have a responsibility to protect both human and animal health through reliable science.

Care before the science begins

Animal care begins before a study is approved. Researchers do not simply decide to use animals and begin an experiment. They must explain why animals are needed, why non-animal alternatives are not enough, how many animals are required, what procedures will be involved, and how any potential discomfort will be minimized. These details are reviewed by an animal care committee composed of individuals with scientific, veterinary, technical, and ethical expertise. This process helps ensure that animal use is justified before it happens.

The people behind animal welfare

Furthermore, animal care is handled around the clock by trained teams, and not simply by researchers. These teams include on-site veterinarians, veterinary technicians, and animal care staff, who all provide proper food and housing, check for signs of illness or distress, and ensure that care practices meet institutional, provincial, and national standards. Care also includes environmental enrichment.

For rodents, this can mean nesting materials, shelters, running wheels and other objects that encourage exploration. Rodents are also primarily housed in social groups, so they can interact with others of their species. This care is not restricted to the facility itself; in Canada, institutions that conduct animal research and receive federal research funding must meet CCAC standards. In Ontario, animal research facilities must also be registered and inspected under provincial law.

Although some people who are unfamiliar with animal research may assume that those who study animals care little for their well-being, my experience has shown me the opposite. In this field, I have met some of the most passionate, careful, and compassionate people I know. Anyone working with animals in research must be extensively trained before doing so. This training covers animal welfare, ethical guidelines, species-specific behaviour, gentle handling, signs of pain or distress, and proper procedures. What has stood out to me is how seriously this responsibility is taken. Even compared with my previous experience as a veterinary assistant and as a volunteer at a primate sanctuary, I have found the research environment to be exceptionally regulated and attentive to animal care.

New tools, careful transitions

New technologies that allow researchers to replace animal testing are always welcome. However, a responsible transition away from animal research must also be careful. If replacement methods are adopted before they are fully validated, they may fail to capture important features of living biology, including whole-body drug effects, development, behaviour, pregnancy, chronic stress, pain, and sex-specific disease mechanisms.

Non-animal methods are already valuable in many areas of biomedical research. Computer models can help predict drug behaviour. Cell-based systems can reveal molecular mechanisms. Organoids can model aspects of human tissue development. These tools can reduce the number of animals used, improve early-stage screening, and sometimes provide more human-specific information than animal models. However, a method can be promising without yet being ready to serve as a full replacement.

Why brain research is hard to replace

Some scientific questions involve systems that cannot yet be fully recreated in a dish or computer model. Brain disorders, for example, involve communication among neural circuits, hormones, immune signals, metabolism, behaviour, stress responses, sleep, development, and environment. These processes involve multiple organs interacting over time. This is especially relevant in my area of Alzheimer’s disease. Alzheimer’s cannot be fully understood at the level of isolated cells alone, because it involves brain circuits, behaviour, aging, immune responses, metabolism, and whole-organism changes over time. While cell-based and computational models are incredibly useful, they cannot yet capture every layer of complexity involved in how the disease develops and progresses.

Progress should not leave bias behind

There is also growing concern within the scientific community that a rapid phase-out of animal research could unintentionally leave existing gaps in biomedical knowledge intact. Preclinical research has historically relied heavily on male animals, especially in neuroscience, meaning that female biology has often been understudied. As a result, female-specific mechanisms of disease, drug response, stress biology, pain, pregnancy, development, and neuropsychiatric vulnerability remain less well understood. If animal research is ended too quickly, before these gaps are addressed, future models may be built on incomplete and biased data.

Toward fewer animals and better science

The future of research should involve fewer animals, better alternatives, and stronger validation. But responsible progress means more than replacing one method with another; it means ensuring that new approaches are humane, reliable, and equitable.

Reference

Kovlyagina, I., Jaric, I. Phasing out animal research prematurely will maintain gender inequities in medicine. Nat Neurosci (2026). https://doi.org/10.1038/s41593-026-02309-w