Richardson, C. A. 2015. The power of automated behavioural homecage technologies in characterizing disease progression in laboratory mice: A review. Applied Animal Behaviour Science 163, 19-27.

Behavioural changes that occur as animals become sick have been characterized in a number of species and include the less frequent occurrence of ‘luxury behaviours’ such as playing, grooming and socialization. ‘Sickness behaviours’ or behavioural changes following exposure to infectious agents, have been particularly well described; animals are typically less active, sleep more, exhibit postural changes and consume less food/water. Disease is frequently induced in laboratory mice to model pathophysiological processes and investigate potential therapies but despite what is known about behavioural changes as animals become sick, behavioural phenotyping of mice involved in disease studies is relatively rare. A detailed understanding of how behaviour changes as mice get sick could be applied to improve welfare of laboratory mice and support the underlying biomedical research. Specifically, characterizing behavioural changes in ill health could help those working with laboratory mice to recognize when refinements should be introduced, when severity limits are being approached and when humane endpoints should be implemented. Understanding how behaviour changes with illness may also help to identify compounds that have a clinical effect as well as when these agents act. There are an increasing number of automated systems to monitor the behaviour of laboratory mice in their homecages incorporating technologies such as the quantification of cage movement, automated video analysis and radiofrequency identification transponders/readers. Mouse models of neurodegenerative diseases particularly Huntington's disease have been well characterized using these systems and behavioural biomarkers of pathology, including changes in the animals’ use of environmental enrichment, changes in food/water consumption and alterations in circadian rhythms, are now monitored by laboratories worldwide and used to refine studies and develop therapies. In contrast, automated behavioural technologies have not been used to characterize the behaviour of mice with systemic diseases such as cancer and liver disease. In this review, common behavioural changes that occur in animals with declining health will be discussed with an emphasis on progressive disease studies involving mice. Automated homecage behaviour recording technologies will then be summarized, studies in which these systems have been used to characterize the behaviour of mice with progressive diseases will be reviewed and the potential to apply automated technologies to refine disease studies involving mice will be discussed.