Returning to animal research: Guide to managing post-pandemic experimental variables

Written  and edited by Dr Nikki Osborne and Dr Vootele Voikar.

The Covid-19 pandemic has undoubtably impacted multiple areas of all our lives, professional and personal. The full impact on the activities of research facilities globally is not yet clear although disruption at every level has been inevitable. At the height of the pandemic it became necessary for many studies including those involving the use of animals to be re-organized and/or disrupted. This was to ensure compliance with local Covid-19 infection control measures, and due to individuals being required to return to clinical work, or diverted to deliver Covid-19 testing services, or other essential research activities.

Within the Laboratory Animal Science sector these challenging times have also seen some potentially positive changes. Many researchers have had the time to investigate developments in alternative methodologies and to revise how they plan and design animal studies. But as efforts are being made to return to pre-pandemic levels of research activity researchers face another new challenge. How to manage a unique set of post-pandemic experimental variables?

Why does this matter?

Anyone who works within the laboratory animal science sector will be aware that there are many different factors that can influence the results of animal studies. This includes:

  • the character traits of individual animals;
  • the actions of the humans they interact with;
  • the regular routine of husbandry and care activities;
  • the ad hoc but precise protocols that dictate the nature and frequency of experimental interactions;
  • the unique blend of sights, smells and sounds that exist within each animal research facility as a result of the presence and activity of humans.

The idea of factors impacting upon animal behaviour and physiology is not new. Indeed these topics are covered very well in the LASA/BNA/BAP/ESSWAP Guiding Principles for Behavioural Laboratory Animal Science1. But as researchers and research facility staff work hard to return research activity levels to pre-pandemic levels it can be easy to overlook. There have been changes that have occurred over the last year and these may have an impact on experimental2 and breeding animals. So is there anything can we do to minimise the potential long-term impact on research of the pandemic? Especially in terms of the reproducibility of research results, and the impact on the animals used to generate them?

Well the first step is to identify and raise awareness of the factors that have changed during the Covid-19 pandemic. This will vary depending on how different animal units are run, and to do this effectively requires a team approach. This is because the lives of most research animals will involve both direct and indirect interactions with multiple individuals.

Often breeding animals are exposed to a smaller selection of individuals and a lower level of human activity. There may be a small team of unit staff responsible for day-to-day husbandry and care, plus individual researchers, or technicians responsible for breeding experimental animals for their research teams. Breeding rooms also often see human activity levels in patterns of regular routines. Despite this the numbers of humans going in and out over the course of a regular working week can be greater than you think, especially in larger rooms housing breeding stock for multiple research groups.

For example, a cage of mice may be impacted by:

  • the frequency of humans walking past the cage;
  • how often cages within the same rack are disturbed;
  • the position of the rack within the room; and
  • the position of the cage within the rack.

Outside of the timeframe of a global pandemic, rooms housing experimental animals will likely witness greater levels of human activity than those housing breeding animals. Experimental animals will also often experience a less regular and more frequent pattern of disturbance. This is because in addition to the team of animal care staff and technicians managing the routine husbandry and care, there is often a larger pool of researchers who will be working with or caring for their experimental animals. Experimental animals may also be more likely to require visits from other key named individuals such as the Named Veterinary Surgeon (NVS) and/ or Named Animal Care and Welfare Officer (NACWO). Thus the volume of human activity within rooms housing experimental animals may well have seen a decline during the pandemic and an increase now restrictions are easing.

The impact that these fluctuations in research activity will have on the reproducibility of research data generated during this period is not yet clear. But with concerns being raised2 this topic is worthy of discussion.


To learn more join Vootele and Nikki for a FREE Responsible Research webinar on Wednesday 23rd June 2021 @10am GMT. After Vootele’s presentation there will be a question and answer session during which Prof Clare Stanford will join the discussions. To register CLICK HERE.


Why attend this webinar?

During this webinar you will hear about:

  • the range of factors that can impact upon the behaviour and physiological responses of experimental animals;
  • steps you can take to take nuisance variables into account when planning and designing your experiments;
  • further guidance and useful resources.



Thanks to Clare Stanford for her helpful comments and feedback on drafts of this blog.



  1. LASA/BNA/BAP/ESSWAP Guiding Principles for Behavioural Laboratory Animal Science (2013)
  2. K Manda. Letter to the Editor: Possible challenges in behavioral phenotyping of rodents following COVID-19 lockdown. (2020) LabAnimal


For details regarding all previous and up coming FREE Responsible Research Webinars visit our website.

Posted in Events, News.