Ten organisations carried out half of all animal research in Great Britain in 2025
Published: 9 July 2026
Ten organisations carried out half of all animal research in Great Britain in 2025
Understanding Animal Research (UAR) has published a list of the 10 organisations that carried out the highest number of animal procedures – those used in medical, veterinary, and scientific research – in Great Britain in 2025.
These statistics are freely available on the organisations’ websites as part of their ongoing commitment to transparency and openness around the use of animals in research.
This list coincides with the publication of the Home Office’s report on the statistics of scientific procedures on living animals in Great Britain in 2025.
The 10 listed organisations were responsible for 1,347,667 procedures, 53% (more than half) of the 2,537,507 procedures carried out on animals for scientific research in Great Britain in 2025*. Of these 1,347,667 procedures, more than 99% were carried out on mice, fish, rats, and birds and 82% were classified as causing pain equivalent to, or less than, an injection.
The 10 organisations are listed below alongside the total number of procedures they carried out in 2025. Each organisation’s name links to its animal research webpage, which includes more detailed statistics. Case studies explaining how animal research has been used in recent medical research are also provided in the Notes to Editors section. This is the eleventh consecutive year that organisations have come together to publicise their collective statistics and examples of their research.
|
Organisation |
Number of Procedures (2025) |
|
216,508 |
|
|
182,562 |
|
|
176,689 |
|
|
167,637 |
|
|
150,817 |
|
|
131,103 |
|
|
106,452 |
|
|
96,038 |
|
|
78,948 |
|
|
40,913 |
|
|
TOTAL |
1,347,667 |
Sixty-nine organisations have proactively published their 2025 animal research statistics including the University of Glasgow.
UAR has also produced a list of 69 organisations in the UK that have publicly shared their 2025 animal research statistics. This includes organisations that carry out or fund animal research.
All organisations are committed to the ethical framework called the ‘3Rs’ of replacement, reduction and refinement. This means avoiding or replacing the use of animals where possible, minimising the number of animals used per experiment and optimising the experience of the animals to improve animal welfare. However, as institutions expand and conduct more research, the total number of animals used can rise even if fewer animals are used per study.
All organisations listed are signatories to the Concordat on Openness on Animal Research in the UK, which commits them to being more open about the use of animals in scientific, medical and veterinary research in the UK. More than 130 organisations have signed the Concordat, including UK universities, medical research charities, research funders, learned societies and commercial research organisations.
Hannah Hobson, Head of Communications and Engagement at Understanding Animal Research, said: “Animal research remains a small but vital part of the quest for new medicines, vaccines and treatments for humans and animals. Alternative methods are increasingly being phased in but, until we have sufficient reliable alternatives available, it is important that organisations that use animals in research maintain the public’s trust in them.
"By providing this level of information about the numbers of animals used, and the experience of those animals, as well as details of the medical breakthroughs that derive from this research, these Concordat on Openness signatories are helping the public to make up their own minds about how they feel about the use of animals in scientific research in Great Britain.”
David Duncan, University of Glasgow Secretary and Deputy Vice Chancellor, said: “Research using animals makes an important contribution to the treatment and cure of major human diseases and viruses, including cancers, Alzheimer’s disease, flu and arthritis. At the University of Glasgow animals are used in research only where it is essential, and we remain dedicated to the principles of reduction, refinement, and replacement.
"The University is committed to the development of alternative methods – such as computer modelling, tissue culture, cell and molecular biology, and research with human material – but some work involving animals must continue for further advances in medical sciences to be made. All research undertaken on animals is conducted under strict ethical and welfare guidelines, under licence by the Home Office.”
These figures published today refer to procedures using animals for medical, veterinary, or scientific research, as licensed by the UK’s Home Office under the Animals (Scientific Procedures) Act 1986. The use of animals to test tobacco products was banned in the UK in 1997 and it has been illegal to use animals to test cosmetic products in this country since 1998. A policy ban on household product testing using animals was introduced in 2010. Since 2013, it has been illegal to sell or import cosmetics anywhere in the UK or the EU where the finished product or its ingredients have been tested on animals.
*The Home Office recorded 2,537,507 completed procedures for Great Britain in 2025, 1,347,667 (53%) of which were carried out at these ten organisations.
All numbers represent completed procedures on animals in 2025. The number of procedures carried out using animals will be slightly higher than the number of animals used, as a small number of animals may be used in more than one procedure.
University of Manchester
Why older mice have smaller offspring – and how sex may play a role
A study by University of Manchester scientists has revealed some of the mechanisms which may explain why older mice are more likely to give birth to offspring that have not grown to their full potential in the womb.
The study in older animals showed that the placentas of male but not female offspring had increased cell damage from a biological state called oxidative stress.
Oxidative stress occurs when harmful molecules called free radicals build up faster than the body can clear them.
It is associated with a range of pregnancy complications including fetal growth restriction and preeclampsia, both of which increase the risk of stillbirth.
The study demonstrated reduced weight in both female and male fetuses in older mice, but the placental alterations were sex-specific.
The scientists are conducting further studies in mice to confirm these findings and also carrying out a parallel study to see if similar sex differentiated mechanisms exist in human placentas from mothers of advanced maternal age (AMA), defined as age 35 and over.
The study, published in the journal Reproduction also discovered placental mitochondria – the biological batteries that power cells – were working at a reduced rate in the placentas of both male and female pups but that there were more of them.
Mitochondria are a major source of free radicals. Reducing their rate of activity at the same time as increasing their numbers is a way they adapt to prevent further oxidative stress while maintaining the supply of energy needed for cells to work properly.
This could mean that the adaptation in placentas from females was more successful than in placentas from males because oxidative stress was not increased in placentas from females of older mice.
Imperial College London
Mouse research identifies a potential new way to prevent cancer spreading
Researchers at Imperial College London and Francis Crick Institute have used mice to investigate how the body's response to respiratory viral infections may help prevent the spread of breast cancer to the lungs. The findings could contribute to the development of new treatments aimed at reducing cancer metastasis.
Cancer spread (metastasis) is responsible for the majority of cancer deaths, and the lungs are one of the most common sites where breast cancer spreads. In this study, researchers used a mouse model to understand how the immune system responds when cancer cells enter the lungs following a respiratory viral infection.
The research found that mice which had recently experienced infection with respiratory syncytial virus infection developed fewer metastatic tumours in their lungs than uninfected mice. The study showed that immune molecules called type I interferons altered the lung environment, making it more difficult for cancer cells to establish new tumours. The researchers also identified a protein called Galectin-9 as playing an important role in limiting the spread of cancer cells.
Animal studies were essential because they allowed researchers to investigate the complex interactions between the immune system, viral infection and cancer spread within a living organism. These processes involve multiple organs and immune responses that cannot yet be fully replicated using cell cultures or computer models alone.
The researchers emphasise that respiratory viruses are not themselves a treatment for cancer. Instead, the findings provide new insights into biological mechanisms that could be used to develop medicines capable of making the lungs more resistant to metastatic cancer in the future. Further studies will be needed to determine whether these findings translate to people.
University of Glasgow case study
Osteoarthritis is the most common form of arthritis and a leading cause of pain, stiffness and loss of mobility, particularly in older adults. Despite its high prevalence, there are currently no treatments that can stop or reverse the disease. Research at the University of Glasgow aims to understand the biological mechanisms that drive osteoarthritis, with a focus on the role of bone cells to identify new therapeutic approaches.
Studying osteoarthritis in humans is challenging because it develops slowly, often over decades. Animal models help to overcome this by allowing research teams to investigate how the disease develops and progresses over a much shorter lifespan, while still reflecting key features of human joint biology.
Led by Dr Carmen Huesa, researchers at the University of Glasgow are currently focused on a protein called PAR2, which accelerates osteoarthritis progression. Using mice in which PAR2 is specifically removed from bone-forming cells, Dr Huesa and her team have demonstrated that osteoblasts actively modify the joint environment in ways that can drive disease. Their findings indicate that altering PAR2 signalling changes how bone cells use energy, which in turn affects joint structure and may slow osteoarthritis progression. These insights are helping to identify new biological pathways that could be targeted therapeutically.
In parallel to this work, Dr Huesa and her team are also investigating how sex and hormonal status influence osteoarthritis. It is already well established that the disease is more common and often more severe in women, particularly after menopause. Using mouse models Dr Huesa’s work has already revealed that hormonal changes can influence joint responses in ways that extend beyond the site of injury, suggesting that menopause-related changes do not only act locally at a damaged joint but can alter the broader joint environment or systemic responses to injury. These findings provide new insight into how hormonal status may amplify or spread osteoarthritis-related changes, highlighting an underappreciated dimension of disease progression.
First published: 9 July 2026