To enrich or not to enrich: providing shelter does not complicate handling of laboratory mice (2004)

Moons, C., Van Wiele, P., ?dberg, F. O.

Abstract

It is argued that when laboratory mice can routinely retreat in sheltering objects when humans are present, they do not habituate to humans and continue to shy away, thereby increasing the time needed for husbandry and testing procedures. ... We housed 20 FVB (inbred) and 20 NMRI (outbred) male mice in standard cages and another 20 FVB and 20 NMRI male mice in cages enriched with two PVC conduits. ... Cage enrichment in the form of PVC conduits decreased the time needed to catch outbred animals and did not increase the time needed to catch mice from the inbred strain. Furthermore, no differences in resistance to being held during the sham injection could be detected between animals from the enriched versus non-enriched group. ... Results indicate that EE [environmental ernichment] in the form of sheltering objects [PVC conduits] does not complicate catching or handling mice and that allowing access to enrichment in the laboratory cage, which has been shown to have positive effects on welfare, does not interfere with the management or cost of laboratory animals. The provision of shelter reduces the time needed to catch and handle NMRI mice.