Why animals are needed
- Nearly every Nobel Laureate in Physiology or Medicine since 1901 has relied on animal data for their research. For example, the 2025 Prize was awarded to three researchers for discovering how the immune system is kept in check, based on studies in mice, while the 2024 Prize went to the researchers who used the roundworm, C. elegans, to discover microRNA and its crucial role in gene regulation. In 2023, the Nobel Prize was awarded for the development of mRNA vaccines for Covid-19, using animals such as mice and monkeys.
- Animals and humans have many similarities, including in their organs, organ systems, body make-up and biological processes. Read the EARA features on why different animals are needed in research.
- We share 95% of our genes with a mouse, making them an effective model for the human body and human diseases. Read our article about why mice are needed in research.
- Animals suffer from similar diseases to humans including cancers (such as mice and zebrafish), Covid-19 (monkeys, hamsters), tuberculosis (cows, pigs), flu (chickens, ferrets) and asthma (cats, dogs).
- CRISPR-Cas9 gene editing was perfected in early studies in animals, leading to ground-breaking discoveries to treat diseases. In little over a decade this has transformed research. Gene editing is routinely used to genetically alter animals (most commonly mice) so that they better mimic or reflect a human disease, for example when the condition does not naturally occur in the animals. This ‘humanisation’ allows relevant diseases to be studied in great depth in a way that is simply not possible in a human. Read the EARA feature How animal studies play their role in a biomedical research revolution.
- All veterinary research and medicine relies on the use of animal research, from vaccines against Marek’s disease (a highly contagious viral disease affecting poultry), to antidepressants for treating a range of ailments in pets, to cancer treatments for dogs, which are naturally affected by many of the same cancers as humans. Read the EARA feature The benefits of animal research to animals.
- Many medicines developed for humans, using animal studies, can also treat animals. Examples include antibiotics, pain killers and tranquillisers. Read the EARA feature The benefits of animal research to animals.
- Many routine medical techniques, including CT and MRI scans, as well as surgical techniques such as hip replacement surgery, heart and kidney transplants, and blood transfusions were all developed using animals. Animal research is also contributing to improving these techniques.
- Pigs and monkeys are important animals for the development and refinement of organ xenotransplantation (transplantation from one species to another – in this case from animals to humans). Recent advances such as the first pig kidney transplant into a living human, and a monkey that survived for two years with a pig kidney, are finding a solution to the critical shortage of organs needed for transplants worldwide. See the EARA feature on pigs.
- While new approach methodologies, including methods that do not rely on animals, play an important part in biomedical research, they currently cannot replace all uses of animals. See the EARA article about new approach methodologies.
Medical breakthroughs due to animal research
- Thanks to animal research, cancer survival rates have continued to rise, and we continue to see promising progress for many other types of cancer. Read our article about cancer research.
- Herceptin – a humanised mouse protein – has helped to increase the survival rate of those with breast cancer; it could not have been attained without animal research in mice. Deaths from this type of cancer, when adjusted for age differences, have dropped by almost half from the 1980s to 2020 due to the use of Herceptin.
- Decades-long studies on coronaviruses in laboratory mice meant that scientists were ready to develop a vaccine to combat Covid-19 during the first year of the pandemic. Read our article about infectious diseases.
- Monkeys played a vital part in the development of Covid-19 vaccines, as their immune systems closely resemble ours and they can naturally catch the disease. Essential tests conducted on monkeys showed that these vaccines were safe and effective before they could be given to people.
- Deep brain stimulation is the main surgical therapy used to manage Parkinson’s disease (also used for other neurological conditions like MS), and was pioneered through critical studies in monkeys. This cutting-edge technique delivers electrical currents to the brain to successfully manage tremors, seizures and other ailments.
- Spinal implants have been investigated in rats and monkeys as a way to treat paralysis and other issues with movement and co-ordination that can arise due to spinal cord injury, which led to people who were paralysed from accidents to successfully stand and walk again.
- Thanks to continuing animal research leading to the development of Highly Active Anti-Retroviral Therapies (HAART), people living with HIV now have a lower risk of developing AIDS, as HAART prevents the virus from replicating and can make it undetectable. This has transformed HIV from a death sentence into a manageable condition, a stark contrast to 40 years ago. More recently, promising advancements have been made in preventing HIV infection altogether, for example through vaccines.
- Animal research is responsible for the development of asthma inhalers. Around 30 million people in Europe are affected by the condition and around 15,000 people die each year from asthma attacks in the continent. Studies in animals have also paved the way for breakthroughs in asthma drugs, responsible for the first new treatment for the condition in 50 years.
- Animal research has helped develop modern vaccines including those against polio, TB, meningitis, and the human papillomavirus (HPV), which has been linked to cervical cancer. Read our article about infectious diseases.
- It was only through studies in monkeys that vaccines for the first major Ebola outbreak in 2015, which caused thousands of deaths in West Africa, could be fast-tracked for human use to bring the disease under control (it also managed a subsequent outbreak in 2018). This speed was also helped by the fact that the first experimental Ebola vaccines were actually developed much earlier, in 2003, as part of curiosity-driven research.
- Many of the treatments for malaria – which kills more than half a million children a year worldwide – exist thanks to research in animals. For example in 2021, a landmark malaria vaccine, developed from mice and monkey studies, was approved by the World Health Organization as the first to provide protection against the disease.
- Animals are being used to develop new ways to investigate disease and understand the human body and scientists use animal experiments alongside and complementary to new approach methodologies, including non-animal methods. In vitro methods, such as cell cultures, organoids and organ-on-chips, as well as computation, such as AI, play an important part in complementing data from animal research. See the EARA feature about new approach methodologies.
How does regulation protect animals
- Animal research can only be carried out in Europe when there is no suitable non-animal alternative, this is enshrined in EU law in Directive 2010/63 which is also closely followed in non-EU countries such as Switzerland and the UK. Read our article about EU regulations on animal research.
- The standards of laboratory animal welfare (how animals should be correctly cared for) in Europe are also outlined in EU Directive 2010/63. Similar standards to ensure the proper regulation and welfare of research animals exist in many other parts of the world, such as the USA, Australia and South Korea.
- Animal testing for cosmetics has been banned in Europe since 2004, with the EU having banned the sale of any cosmetics or cosmetics ingredients that have been tested on animals since March 2013. Read our article about EU regulations on animal research.
- Research on great apes (orang-utans, bonobos, gorillas and chimpanzees) is banned in the EU under Directive 2010/63. The only exceptions for their use in research are for the preservation of those species, or where a life-threatening or debilitating condition endangering humans cannot be studied in any other species or by any other method.
- In the EU all animal researchers, projects and facilities conducting, or related, to animal research must be authorised by national regulatory bodies. Read our article about EU regulations on animal research.
- All project proposals that require the use of animals also have to be approved by the individual ethics committee from any institution that conducts animal research. The research will not be allowed if the potential benefits of research do not outweigh the suffering that might be experienced by the animals used. Read our article about animal research in the EU.
- There is a legal requirement to replace animals with alternatives, refine experimental techniques and reduce the number of animals used in research – defined as the 3Rs . These are the accepted standards for research with animals and are part of the everyday practice of researchers and lab staff across the world. See our page "Replace, reduce, refine".
- Despite the progress of alternatives to animal research, such as new approach methodologies (NAMs) that do not require animals in regulatory testing, a complementary approach that employs both animal and non-animal methods together will provide the best understanding for basic and translational research, as well as testing. See our feature on NAMs.