Recommended Set

15. Housing and husbandry

The environment determines the health and wellbeing of the animals and every aspect of it can potentially affect their behavioural and physiological responses, thereby affecting research outcomes [1]. Different studies may be sensitive to different environmental factors, and particular aspects of the environment necessary to report may depend on the type of study [2]. Examples of housing and husbandry conditions known to affect animal welfare and research outcomes are listed in the table below; consider reporting these elements and any other housing and husbandry conditions likely to influence the study outcomes.

Examples of information to consider when reporting housing and husbandry, and their effects on laboratory animals

Information to report

Examples of effects on laboratory animals

Cage/tank/housing system (type and dimensions)

Affects behaviour[3] and fear learning [4]. Tank colour affects stress in aquatic species [5,6].

Food and water (type, composition, supplier and access)

Affects body weight, tumour development, nephropathy severity [7], and the threshold for developing Parkinsonian symptoms [8]. Maternal diet affects offspring body weight [9].

Bedding and nesting material

Affects behavioural responses to stress [10] and pain [11].

Temperature and humidity

Modifies tumour progression [12]. Regulates sexual differentiation in zebrafish [13].

Sanitation (frequency of cage/tank water changes, material transferred, water quality)

Affects blood pressure, heart rate, behaviour [14]. Adds an additional source of variation [15,16].

Social environment (group size and composition/stocking density)

Compromises animal welfare [17]. Induces aggressive behaviour [18,19] and stress [6].

Biosecurity (level)

The microbiological status of animals causes variation in systemic disease parameters [20].

Lighting (type, schedule and intensity)

Modifies immune and stress responses [21].

Environmental enrichment


Reduces anxiety [22,23], stress [22,23] and abnormal repetitive behaviour [24-26]. Reduces susceptibility to epilepsy [27] and osteoarthritis [28] and modifies the pathology of neurological disorders [29]. Increases foraging behaviour in fish [30].

Sex of the experimenter

Affects physiological stress and pain behaviour [31].

Environment, either deprived or enriched, can affect a wide range of physiological and behavioural responses [32]. Specific details to report include, but are not limited to, structural enrichment (e.g. elevated surfaces, dividers), resources for species-typical activities (e.g. nesting material, shelters or gnawing sticks for rodents; plants or gravel for aquatic species), toys or other tools used to stimulate exploration, exercise (e.g. running wheel), and novelty. If no environmental enrichment was provided, this should be clearly stated with justification. Similarly, scientific justification needs to be reported for withholding food and water [33], and for singly housing animals [34,35].

If space is an issue, relevant housing and husbandry details can be provided in the form of a link to the information in a public repository, or as supplementary information.



  1. Nevalainen T (2014). Animal husbandry and experimental design. ILAR J. doi: 10.1093/ilar/ilu035
  2. (2014). Guidance for the description of animal research in scientific publications. ILAR J. doi: 10.1093/ilar/ilu070
  3. Bailoo JD, Murphy E, Varholick JA, Novak J, Palme R and Würbel H (2018). Evaluation of the effects of space allowance on measures of animal welfare in laboratory mice. Scientific reports. doi: 10.1038/s41598-017-18493-6
  4. Kallnik M, Elvert R, Ehrhardt N, Kissling D, Mahabir E, Welzl G, Faus-Kessler T, de Angelis MH, Wurst W, Schmidt J and Holter SM (2007). Impact of IVC housing on emotionality and fear learning in male C3HeB/FeJ and C57BL/6J mice. Mamm Genome. doi: 10.1007/s00335-007-9002-z
  5. Holmes AM, Emmans CJ, Jones N, Coleman R, Smith TE and Hosie CA (2016). Impact of tank background on the welfare of the African clawed frog, Xenopus laevis (Daudin). Applied Animal Behaviour Science. doi: 10.1016/j.applanim.2016.09.005
  6. Pavlidis M, Digka N, Theodoridi A, Campo A, Barsakis K, Skouradakis G, Samaras A and Tsalafouta A (2013). Husbandry of zebrafish, Danio rerio, and the cortisol stress response. Zebrafish. doi: 10.1089/zeb.2012.0819
  7. Haseman JK, Ney E, Nyska A and Rao GN (2003). Effect of diet and animal care/housing protocols on body weight, survival, tumor incidences, and nephropathy severity of F344 rats in chronic studies. Toxicol Pathol. doi: 10.1080/01926230390241927
  8. Morris JK, Bomhoff GL, Stanford JA and Geiger PC (2010). Neurodegeneration in an animal model of Parkinson's disease is exacerbated by a high-fat diet. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. doi: 10.1152/ajpregu.00449.2010
  9. Bayol SA, Farrington SJ and Stickland NC (2007). A maternal 'junk food' diet in pregnancy and lactation promotes an exacerbated taste for 'junk food' and a greater propensity for obesity in rat offspring. Br J Nutr. doi: 10.1017/S0007114507812037
  10. Gaskill BN and Garner JP (2017). Stressed out: providing laboratory animals with behavioral control to reduce the physiological effects of stress. Lab Animal. doi: 10.1038/laban.1218
  11. Robinson I, Dowdall T and Meert TF (2004). Development of neuropathic pain is affected by bedding texture in two models of peripheral nerve injury in rats. Neurosci Lett. doi: 10.1016/j.neulet.2004.06.078
  12. Kokolus KM, Capitano ML, Lee CT, Eng JW, Waight JD, Hylander BL, Sexton S, Hong CC, Gordon CJ, Abrams SI and Repasky EA (2013). Baseline tumor growth and immune control in laboratory mice are significantly influenced by subthermoneutral housing temperature. Proceedings of the National Academy of Sciences of the United States of America. doi: 10.1073/pnas.1304291110
  13. Lawrence C (2007). The husbandry of zebrafish (Danio rerio): A review. Aquaculture.
  14. Duke JL, Zammit TG and Lawson DM (2001). The effects of routine cage-changing on cardiovascular and behavioral parameters in male Sprague-Dawley rats. Contemp Top Lab Anim Sci.
  15. Prager E, Bergstrom H, Grunberg N and Johnson L (2011). The Importance of Reporting Housing and Husbandry in Rat Research. Front Behav Neurosci. doi: 10.3389/fnbeh.2011.00038
  16. Rosenbaum MD, VandeWoude S and Johnson TE (2009). Effects of Cage-Change Frequency and Bedding Volume on Mice and Their Microenvironment. Journal of the American Association for Laboratory Animal Science : JAALAS.
  17. Kappel S, Hawkins P and Mendl MT (2017). To Group or Not to Group? Good Practice for Housing Male Laboratory Mice. Animals : an Open Access Journal from MDPI. doi: 10.3390/ani7120088
  18. Van Loo PLP, Mol JA, Koolhaas JM, Van Zutphen BFM and Baumans V (2001). Modulation of aggression in male mice: influence of group size and cage size. Physiology & behavior. doi: 10.1016/S0031-9384(01)00425-5
  19. Adams CE, Turnbull JF, Bell A, Bron JE and Huntingford FA (2007). Multiple determinants of welfare in farmed fish: stocking density, disturbance, and aggression in Atlantic salmon (Salmo salar). Can J Fish Aquat Sci. doi: 10.1139/F07-018
  20. Bleich A and Hansen AK (2012). Time to include the gut microbiota in the hygienic standardisation of laboratory rodents. Comparative immunology, microbiology and infectious diseases. doi: 10.1016/j.cimid.2011.12.006
  21. Dauchy RT, Dupepe LM, Ooms TG, Dauchy EM, Hill CR, Mao L, Belancio VP, Slakey LM, Hill SM and Blask DE (2011). Eliminating animal facility light-at-night contamination and its effect on circadian regulation of rodent physiology, tumor growth, and metabolism: a challenge in the relocation of a cancer research laboratory. J Am Assoc Lab Anim Sci.
  22. Chapillon P, Manneché C, Belzung C and Caston J (1999). Rearing Environmental Enrichment in Two Inbred Strains of Mice: 1. Effects on Emotional Reactivity. Behavior Genetics. doi: 10.1023/a:1021437905913
  23. Hendershott TR, Cronin ME, Langella S, McGuinness PS and Basu AC (2016). Effects of environmental enrichment on anxiety-like behavior, sociability, sensory gating, and spatial learning in male and female C57BL/6J mice. Behavioural brain research. doi: 10.1016/j.bbr.2016.08.004
  24. Garner JP (2005). Stereotypies and other abnormal repetitive behaviors: potential impact on validity, reliability, and replicability of scientific outcomes. ILAR journal. doi: 10.1093/ilar.46.2.106
  25. Gross AN-M, Engel AKJ and Würbel H (2011). Simply a nest? Effects of different enrichments on stereotypic and anxiety-related behaviour in mice. Applied Animal Behaviour Science. doi: 10.1016/j.applanim.2011.06.020
  26. Wurbel H (2001). Ideal homes? Housing effects on rodent brain and behaviour. Trends in neurosciences. doi: 10.1016/s0166-2236(00)01718-5
  27. Auvergne R, Déan C, El Bahh B, Arthaud S, lespinet-najib v, Rougier A and Le Gal La Salle G (2002). Delayed kindling epileptogenesis and increased neurogenesis in adult rats housed in an enriched environment. doi: 10.1016/S0006-8993(02)03355-3
  28. Salvarrey-Strati A, Watson L, Blanchet T, Lu N and Glasson SS (2008). The influence of enrichment devices on development of osteoarthritis in a surgically induced murine model. ILAR 
  29. Hannan AJ (2014). Environmental enrichment and brain repair: harnessing the therapeutic effects of cognitive stimulation and physical activity to enhance experience-dependent plasticity. Neuropathology and applied neurobiology. doi: 10.1111/nan.12102
  30. Braithwaite VA and Salvanes AGV (2005). Environmental variability in the early rearing environment generates behaviourally flexible cod: implications for rehabilitating wild populations. P Roy Soc B-Biol Sci. doi: 10.1098/rspb.2005.3062
  31. Sorge RE, Martin LJ, Isbester KA, Sotocinal SG, Rosen S, Tuttle AH, Wieskopf JS, Acland EL, Dokova A, Kadoura B, Leger P, Mapplebeck JCS, McPhail M, Delaney A, Wigerblad G, Schumann AP, Quinn T, Frasnelli J, Svensson CI, Sternberg WF and Mogil JS (2014). Olfactory exposure to males, including men, causes stress and related analgesia in rodents. Nature Methods. doi: 10.1038/nmeth.2935
  32. Kotloski RJ and Sutula TP (2015). Environmental enrichment: evidence for an unexpected therapeutic influence. Experimental neurology. doi: 10.1016/j.expneurol.2014.11.012
  33. Jensen TL, Kiersgaard MK, Sorensen DB and Mikkelsen LF (2013). Fasting of mice: a review. Lab Anim. doi: 10.1177/0023677213501659
  34. National Research Council (2011). Guide for the Care and Use of Laboratory Animals. 8th Edition. The National Academies Press. doi: 10.17226/12910
  35. European Commission (2010). Directive 2010/63/EU of the European Parliament and of the Council of 22 September 2010 on the protection of animals used for scientific purposes. Available at:

Example 1

“Breeding colonies were kept in individually ventilated cages (IVCs; Tecniplast, Italy) at a temperature of 20°C to 24°C, humidity of 50% to 60%, 60 air exchanges per hour in the cages, and a 12/12-hour light/dark cycle with the lights on at 5:30 AM. The maximum caging density was five mice from the same litter and sex starting from weaning. As bedding, spruce wood shavings (Lignocel FS-14; J. Rettenmaier und Soehne GmbH, Rosenberg, Germany) were provided. Mice were fed a standardized mouse diet (1314, Altromin, Germany) and provided drinking water ad libitum. All materials, including IVCs, lids, feeders, bottles, bedding, and water were autoclaved before use. Sentinel mice were negative for at least all Federation of laboratory animal science associations (FELASA)-relevant murine infectious agents…as diagnosed by our health monitoring laboratory, mfd Diagnostics GmbH, Wendelsheim, Germany.” [1]

Example 2

“Same sex litter mates were housed together in individually ventilated cages with two or four mice per cage. All mice were maintained on a regular diurnal lighting cycle (12:12 light:dark) with ad libitum access to food (7012 Harlan Teklad LM-485 Mouse/Rat Sterilizable Diet) and water. Chopped corn cob was used as bedding. Environmental enrichment included nesting material (Nestlets, Ancare, Bellmore, NY, USA), PVC pipe, and shelter (Refuge XKA-2450-087, Ketchum Manufacturing Inc., Brockville, Ontario, Canada). Mice were housed under broken barrier-specific pathogen-free conditions in the Transgenic Mouse Core Facility of Cornell University, accredited by AAALAC (The Association for Assessment and Accreditation of Laboratory Animal Care International).” [2]



  1. Heykants M and Mahabir E (2016). Estrous cycle staging before mating led to increased efficiency in the production of pseudopregnant recipients without negatively affecting embryo transfer in mice. Theriogenology. doi: 10.1016/j.theriogenology.2015.10.027
  2. Gallastegui A, Cheung J, Southard T and Hume KR (2018). Volumetric and linear measurements of lung tumor burden from non-gated micro-CT imaging correlate with histological analysis in a genetically engineered mouse model of non-small cell lung cancer. Lab Anim. doi: 10.1177/0023677218756457