Facts and figures

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

Graphic and bar chart showing animals involved in research in 2020

Graphic - research involving animals in 2020

Bar chart - research involving animals in 2020


Tables showing animals involved in research 2015–2020

Figures for 2020 as a table

Table showing animals involved in research in 2020

Species 2020
Zebrafish 23,453
Mice 16,603
Birds 294
Rats 173
Gerbils 8
Pigs 5

Figures for 2015–2019 as a table

Table showing animals involved in research 2015 to 2019

Species 2019 2018 2017 2016 2015
Fish 44,381 44,068 51,717 57,819 59,564
Mice 23,824 21,580 30,707 24,132 21,294
Birds 239 173 138 274 1,111
Rats 229 272 684 821 404
Rabbits 40 59 30 40 66
Gerbils 20 32 21 20 43
Pigs 7 5 3 24 30
Total 68,740 66,189 83,300 83,130 82,512


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 e.g. 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, 2017–2018

Procedures, 2016-17

Figure 2: Actual severity, 2020

Threshold 2020

Figure 3: Actual severity, 2017–2018

Threshold 2016