In March, the European Commission released the latest statistics on the use of animals in research and testing in the EU and Norway for 2023. Overall, the total number of all animal uses for research, testing, routine production and education decreased to 8.08 million procedures compared to 2022, which is a reduction of 4.7%. Moreover, the total number of animals used for the first time was 7.97 million, a decrease of 4.9% compared to 2022.

The summary below describes figures specifically related to ‘severe’ suffering.

Statistics on ‘severe’ suffering

In the EU and Norway, 8.7% of procedures (703,461) were classified as severe, representing a decrease of 10.2% since 2022. 

Species

The most commonly used animals to experience severe suffering were:

• Mice 438,731 (62.4%)
• Salmon, trout, char and grayling 58,576 (8.3%) 
• Rats 53,209 (7.6%)
• Other fishes (other than zebrafish) 42,082 (6%)
• Zebrafish 32,119 (4.6%)
   

Purposes of animal use

The highest number of severe procedures were for basic research (263,117; 37.4%), followed by translational and applied research (247,046; 35.1%), and regulatory use and routine production (177,790; 25.3%).

 

In basic research, the highest number of severe uses involved studies of the nervous system (88,292; 33.6%), the immune system (55,077; 20.9%), and oncology (47,507; 18.1%).

 

The highest number of severe uses in translational and applied research involved studies of animal diseases and disorders (93,931; 38%), human cancer (46,897; 19%), and other human nervous and mental disorders (31,818; 12.9%).

The production of monoclonal antibodies by the mouse ascites method accounted for 90.7% (34,229) of severe uses within routine production. Meanwhile, quality control (including batch safety and potency testing) and toxicity and other safety testing, including pharmacology, represented 64.9% (90,927) and 31.2% (43,642), respectively, of regulatory uses.

Main areas of concern

The report also details specific areas of concern where high numbers of animals are subject to a high proportion of severe uses. These include:

• Mice used for monoclonal antibody production via the ascites method
• Fishes used for batch potency testing 
• Fishes used for studies on the immune system 
• Rodents used for studies on human immune disorders
• Rodents used for LD50/LC50 testing
• Fishes used for acute toxicity testing

Conclusion

Since 2018, while the total number of animal procedures across different research fields has fluctuated, there has been a consistent decline in procedures causing severe suffering. However, in some areas, particularly in regulatory testing and routine production, the number of animals experiencing severe suffering has increased in recent years. This is likely due to improved reporting following the 2021 amendment to these categories, including adding more granularity (e.g. clear justification for the test), linking animal use to the specific legislative requirement, reporting actual severity of procedures, etc. 

Given the severe nature of these procedures, prioritising refinements and the development and implementation of alternative approaches is essential to minimise animal suffering. 

Acute toxicity tests are mostly conducted in zebrafish; while these tests are conducted following OECD guidelines, mandating strict adherence to the 3Rs, the animals used in these experiments are still subject to severe suffering. For this reason, we are collaborating with various stakeholders in this field to develop a framework for the standardisation of humane endpoints in fish toxicology. You can read more about our work in this area and our recommendations here.

The production of monoclonal antibodies by the mouse ascites method continues to be a concern. This method involves the development of large, painful tumours that cause significant animal suffering. Since alternative approaches are already available, the justification for continuing to use this method should be rigorously scrutinised. Most of these procedures are conducted in a single Member State, France, despite all other Member States having transitioned to alternative approaches and/or no longer permitting the use of this method.

Nonetheless, the overall continuing reduction in animal numbers and severe procedures attest to the scientific community’s commitment to ending lab animal suffering. We will continue to collaborate with scientists, veterinarians, animal technologists, regulators and animal ethics committees to help achieve further refinements, as part of our work to end animal suffering and promote the fullest implementation of the 3Rs.