The influences of standard laboratory cages on rodents and the validity of research data

Abstract

AbstractStandard cages for laboratory animals are often small, minimalist and barren. Such cages can compromise animal welfare, indicating that there are welfare-based reasons for improving their designs. However, a second issue, that is, whether animals from standard laboratory housing and husbandry conditions provide valid research data, also indicates that cage designs and husbandry methods need to be improved. This paper reviews various influences of standard laboratory cage design and husbandry. These include their effects on the repeatability of studies, models of neuro-degenerative disease, sensory development, physiology, and behaviour, the effects of standard social housing and standard handling, and the effects of maternal experience on the responses of offspring. These studies show that the development and responses of animals from standard laboratory housing and husbandry conditions are often unrepresentative and idiosyncratic, indicating that data are likely to have reduced external validity. An underlying question is whether animals from standard, barren laboratory cages are ‘abnormal’ and therefore might not provide valid baseline data. In terms of animal welfare, these studies indicate that standard laboratory housing may sometimes be associated both with reduced welfare and with reduced benefits gained from research. It is suggested that in a similar manner to the use of production measures when assessing cages for production animals, laboratory cages could be assessed in terms of their suitability to provide valid research data.