Facts and figures

Studies involving animals are only a small part of our overall programme of medical and scientific research.


Our research

Most of our research is carried out using techniques such as cell and tissue culture, molecular biology, computer modelling and the study of samples from humans.

This approach provides us with opportunities to develop a deeper understanding of health and disease, leading to the development of novel treatments and therapies to alleviate symptoms.

We only use animals where no other alternatives are available. Wherever possible we use species of the lowest neurophysiological sensitivity.

The vast majority of our animal research involves zebrafish, mice and rats. Breeding and maintenance of genetically altered animals is classed as a procedure and therefore the vast majority of our procedures returned to the Home Office each year are a record of those breeding programmes. Most other procedures involve injections or blood sampling similar to what we would receive if visiting our GP or nurse.

Just like humans if animals undergo surgery, we use anaesthetics appropriate for the species. In addition, painkillers are administered where appropriate as pain should always be minimised to improve animal welfare producing better outcomes for our programmes of research

We gather data on the number of procedures performed using animals.

Research involving animals at the University of Sheffield

Figures for 2022 as a table

Table showing animals involved in research in 2022

Species 2022
Zebrafish 25,045
Mice 20,546
Birds 249
Rats 56
Gerbils 22
Pigs 23

Figures for 2016–2021 as a table

Table showing animals involved in research 2016 to 2021

Species 2021 2020 2019 2018 2017 2016
Fish 28,105 23,453 44,381 44,068 51,717 57,819
Mice 25,808 16,603 23,824 21,580 30,707 24,132
Birds 270 294 239 173 138 274
Rats 81 173 229 272 684 821
Rabbits 0 0 40 59 30 40
Gerbils 26 8 20 32 21 20
Pigs 14 5 7 5 3 24
Total 54,304 40,536 68,740 66,189 83,300 83,130

Regulated procedures

We gather data on the number of procedures performed using animals (Figure 1) each year and these are submitted to the Home Office. We also gather information on what is known as the actual severity (Figures 2 and 3) that each animal has experienced throughout the course of its experimental life.

The categories are:

  • sub-threshold, denoting an animal that has not suffered, ie this could be a genetically altered animal that has been part of a breeding programme
  • mild, for example removal of blood, similar to what may happen when you visit the nurse
  • moderate, an example would be a surgical procedure such as vasectomy
  • severe, this category is the highest in the UK and is only allowed when the science has been well justified to ensure that any suffering is of short duration, an example may be a model that develops a neurological disorder eg multiple sclerosis
  • non-recovery, this classification is reserved for those animals that undergo a procedure under terminal anaesthesia.

Most of our animal research falls within the sub-threshold and mild categories and this is achieved through stringent ethical review prior to any animal being used in our research.

Figure 1: Total number of regulated procedures, 2021–2022

Pie chart showing the total number of regulated procedures 2021-2022
Pie chart showing the total number of regulated procedures 2021-2022

Figure 2: Actual severity, 2021-2022

Pie chart showing the severity of procedures
Pie chart showing the severity of procedures

Table showing the severity of procedures 

Severity of procedures 2021 2022
Non-recovery  626, 1.15% 268, 0.58%
Sub-threshold 26,286, 48.41% 21,052, 45.82%
Mild 22,214, 40.91% 21,579, 46.97%
Moderate  4779, 8.8% 2769, 6.03%
Severe 398, 0.73% 273, 0.59%

Centres of excellence

The University's cross-faculty research centres harness our interdisciplinary expertise to solve the world's most pressing challenges.