Refinement of gerbil housing and husbandry in the laboratory.

Mongolian gerbils, Meriones unguiculatus, are widely used as model species in parasitology, and in research on epilepsy and ischaemia. When kept under standard laboratory housing conditions, gerbils develop two distinctive behavioural abnormalities: stereotypic digging and bar chewing. Our work centred on assessing the mechanisms leading to these stereotypies. We aimed at finding practical housing and husbandry solutions that would prevent the development of such stereotypies in the laboratory by addressing the behavioural needs of gerbils. Faecal cortisol levels were used as a non-invasive method to compare stress reactions in gerbils housed under different conditions. Stereotypic digging was caused by the lack of a burrow in the laboratory cage, while stereotypic bar chewing was caused by premature separation of juveniles from their family before the birth of younger siblings. An integrated artificial burrow system is presented that prevents the development of stereotypic digging in gerbils, and adaptations in husbandry routines are suggested that significantly reduce the incidence of bar chewing. We conclude that simple refinement of housing is effective in improving gerbil welfare in the laboratory.