Effects of Environmental Enrichment for Mice: Variation in Experimental Results

This study focused on the effects of different enriched environments for mice in a number of behavioral and physiological parameters in 2 routine laboratory testing procedures: potency testing for tetanus vaccine and stress-induced hyperthermia. The variability in the results was studied by calculating and analyzing mean absolute devi-ations. Mice from enriched conditions weighed more and […]

Cage enrichment and mouse behaviour

Mice housed in standard cages show impaired brain development, abnormal repetitive behaviours (stereotypies) and an anxious behavioural profile, all of which can be lessened by making the cage environment more stimulating. But concerns have been raised that enriched housing might disrupt standardization and so affect the precision and reproducibility of behavioural-test results (for example, see […]

Middle-aged mice with enrichment-resistant stereotypic behaviour show reduced motivation for enrichment

For captive animals, living in barren conditions leads to stereotypic behaviour that is hard to alleviate using environmental enrichment. This resistance to enrichment is often explained via mechanisms that decouple abnormal behaviour from current welfare, such as ‘establishment’: a hypothetical process whereby repetition increases behaviour’s predictability and resistance to change. If such hypotheses are correct, […]

Leaving home: A study of laboratory mouse pup independence

Juvenile wild house mice leave their mothers at 8 weeks (+). In contrast, laboratory strains of mice (lab mice) are typically ‘weaned’ at postnatal day (PND) 21. Lab mice might mature faster than their wild forebears; but if they do not, standard laboratory weaning likely involves maternal deprivation. We therefore investigated when lab mice voluntarily […]

Nesting Material as Environmental Enrichment Has No Adverse Effects on Behavior and Physiology of Laboratory Mice

Environmental enrichment may improve the quality of life of captive animals by altering the environment of animals so that they are able to perform more of the behavior that is within the range of the animal’s species-specific repertoire. When enrichment is introduced into an animal’s environment, it is important to evaluate the effect of the […]

Identification of appropriate measures for the assessment of laboratory mouse welfare

A Delphi consultation process was used to examine the validity and feasibility of potential resource-input and animal-based outcome measures of laboratory mouse welfare identified by a comprehensive literature search. The consultation was an iterative two-stage technique that used web and email based questionnaires to gather data. On completion of the second consultation stage a total […]

Preferences of Laboratory Mice For Characteristics of Soiling Sites

When designing cages to maximize welfare, we should consider both the physical and psychological needs of the animals for which the cage is intended. Many laboratory species show non-random defecation patterns and therefore might possess a psychological need for soiling sites with preferred characteristics. This study examined whether caged laboratory mice preferred to defecate on […]

The effect of two different Individually Ventilated Cage systems on anxiety-related behaviour and welfare in two strains of laboratory mouse

The environment in which a laboratory animal is housed can significantly influence its behaviour and welfare, acting as a potential confounding factor for those studies in which it is utilised. This study investigated the impact of two Individually Ventilated Cage (IVC) housing systems on anxiety-related behaviour and welfare indicators in two common strains of laboratory […]

Looking on the bright side of bias—Validation of an affective bias test for laboratory mice

Based on the concept that experience-dependent memory may be biased by affective state at the time of learning, the affective bias test represents a novel approach for the assessment of emotions in animals. The task uses a within-subjects study design, where animals encounter two independent discrimination tasks on separate test days and learn that digging […]

Abnormal behaviour with a focus on stereotypies – indicators of suffering and impaired welfare?

Abnormal behaviour is a potential indicator of pain, suffering and injury in captive animals. Especially stereotypies, i.e. repetitive invariant behavioural patterns without obvious function or goal, can be observed as a consequence of inadequate housing conditions. Hence, they are often considered indicators of impaired welfare. In context of the ongoing scientific debate on captive animal […]