Conventional laboratory housing increases morbidity and mortality in research rodents: Results of a meta-analysis (2022)

Cait, J., Cait, A., Scott, R. W. et al.

Abstract

Over 120 million mice and rats are used annually in research, conventionally housed in shoebox-sized cages that restrict natural behaviours (e.g. nesting and burrowing). This can reduce physical fitness, impair thermoregulation and reduce welfare (e.g. inducing abnormal stereotypic behaviours). In humans, chronic stress has biological costs, increasing disease risks and potentially shortening life. Using a pre-registered protocol (https://atrium.lib.uoguelph.ca/xmlui/handle/10214/17955), this meta-analysis therefore tested the hypothesis that, compared to rodents in ‘enriched' housing that better meets their needs, conventional housing increases stress-related morbidity and all-cause mortality.