Refinement of gerbil housing and husbandry in the laboratory
Mongolian gerbils (Meriones unguiculatus) are a widely used model species in parasitology and epilepsy research. Under standard laboratory housing conditions gerbils develop stereotypic digging, a behavioural abnormality, which is caused by the lack of a burrow in the laboratory
cage. Here we show that gerbils reared with access to an opaque artificial burrow (nest-box with access tube) develop significantly less stereotypic digging than those reared with transparent artificial burrows. Subadult gerbils also preferred opaque artificial burrows to transparent ones.
Based on these findings we developed an artificial burrow system that could be integrated into laboratory Makrolon Type IV cages to prevent the development of stereotypic digging in gerbils by addressing their behavioural needs. Faecal cortisol levels were measured as a non-invasive method
of comparing stress reactions in gerbils given access to the new integrated artificial burrow system or to an equivalent transparent burrow. Behavioural differences were observed between gerbils in the two housing conditions, but faecal cortisol levels were unaffected. We conclude that simple
refinement of housing is effective in improving gerbil welfare in the laboratory.