What does the increase in numbers of animals used in research mean?

Posted on July 10, 2012 by


The government has published figures for the number of procedures using animals for scientific research in the UK during 2011. There has been a 2% increase on 2010’s figures. An increased emphasis on fundamental research  – studying animals to better understand physiology, genetics and biochemistry – accounts for much of this. Both the government and the whole bioscience community, including medical research charities, is committed to reducing the numbers of animals used in research and maintaining the highest welfare standards.  The NC3Rs was appointed by the government to lead this work and has this week launched a new evaluation system to better monitor our progress.


Every year, the Home Office publishes the number of procedures carried out using animals in the UK. You can see past figures here. Procedures can be actual experiments – like changing a rat’s diet to see if it gets fatter – but the definition also includes the mating of genetically modified (GM) animals. The increasing use of GM animals, requiring more breeding to get specific genetic strains, has resulted in a 42% increase in animal procedures since 2001. One procedure usually accounts for one animal but sometimes more than one procedure will be carried out on one animal.

Research using animals has led to many advances in the treatment of debilitating and life-threatening diseases. Chemotherapy, kidney dialysis, heart transplants, IVF – animal research was a vital part of the development of all of these. Animals also help us to understand physiology, genetics and biochemistry – fundamental research that underpins all scientific and medical progress that follows.

All AMRC members sign up to the AMRC position statement in support of animal research. This states that it should only be conducted when there’s no alternative approach available and where the research is carried out according to best practice as laid down in legislation. This includes following the 3Rs – working to replace, refine and reduce the number of animals used in research.

The UK has a dedicated National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), which funds research and initiatives into alternatives. The Coalition Government agreement included a pledge to work to reduce the use of animals in research and testing – this work is led by the NC3Rs. Last week David Willetts earmarked £3m of the MRC’s budget specifically to support the centre’s open innovation programme CRACK IT (I’ll be discussing that in a few weeks’ time on this blog – stay tuned!).

UK regulations governing animal research are currently being updated in response to a new EU Directive. This largely brings standards across the EU closer to those we already have in the UK – more detail on how the government plans to update the law here.

AMRC is clear that we do not want to see any reduction in animal welfare in the UK.

What are the figures?

Just over 3.79 million scientific procedures were started in the UK in 2011, an increase of 2% compared to 2010 (meaning 68,100 more animals were used in 2011). Breeding of GM animals and harmful mutants (HM), mainly mice, remained stable, accounting for 1.62 million procedures.

Excluding the breeding of GM and HM animals, the total number of procedures increased in 2011 by 3% (or 71,300 animals).

There were increases in numbers of procedures for several species, for example cats (153 animals in 2011, up by 23% from 2010), pigs (3,962, up 37%), birds (162,618, up 14%) and fish (563,903, up 15%). But there were also falls for several species, for example rats (271,535 in 2011, down by 11%), guinea pigs (11,537, down 16%), dogs (4,552, down 21%) and non-human primates (down 47%) with new world monkeys (351, all Marmosets or Tamarin monkeys, down 68%) and old world monkeys (2,124 Macaques, down 41%).

There was an increase of 2% in the numbers of procedures for safety testing (toxicology) to 399,000, due to increased use of fish in regulatory toxicology. Most toxicology procedures are carried out in the commercial sector where the number of procedures also rose (+1%).

The number of non-toxicology procedures increased 2% to 3.39 million, reflecting the higher numbers of procedures carried out in universities (+7%), particularly in fundamental research. Notably, physiology, immunology and parasitology accounted for increases in animal use.

All documents and supplementary figures are available here.

What does this mean for medical research?

In part, more procedures is an indicator of more research underway, which is a good thing for improving healthcare and fighting disease: UK expenditure on biomedical research more than doubled in real terms from 1997 to 2009 and the number of animal procedures increased by just over one third. It also reflects a change of emphasis in the research we are doing; for example more fundamental research – studying animal models to better understand physiology, immunology and parasitology – contributes to an increase.

Although on the face of it a rise in the number of animals being used suggests that we are not successfully reducing the number of animals used in research, the NC3Rs themselves are clear that these figures are not helpful in assessing the impact of the 3Rs. There is not enough detail to see how how higher-welfare methods are being used to reduce suffering for example, and how the experiments that are underway have reduced the number of animals used. NC3Rs are proposing a new more detailed data collection framework to help monitor our success in this area and ensure we can keep improving the 3Rs.

The biomedical research sector remains dedicated to the 3Rs and AMRC continues to work with our members to help them fund the highest quality and highest welfare medical research, including working with the NC3Rs.

If you would like to know more about animal research why not check out our Q&A.

Posted in: Policy