Impact of 'living apart together' on postoperative recovery of mice compared with social and individual housing

Social housing is the optimal way of housing female laboratory mice. However, individual housing may be required in experimental designs, for example after surgery. We therefore investigated whether housing two female mice in a cage, separated by a grid partition ('living apart together', LAT), counters the adverse effects of individual housing on postoperative recovery. Ten individually housed (IND) mice, nine socially housed (SOC) mice and nine mice, housed LAT, were surgically implanted with a telemetry transmitter. From one week prior to surgery until three weeks thereafter, several physiological and behavioural parameters were measured in the mice subjected to surgery. The telemetry transmitter measured heart rate (HR), body temperature and activity continuously. Body weight, food and water intake were scored regularly, as were wound healing, ease of handling, nest building and behaviour. Results indicated that SOC mice appear to be less affected by abdominal surgery than IND mice, as indicated by HR and behaviour. LAT, however, did not appear to be beneficiary to the mice. Increased HR levels and differences in behaviour as compared with both SOC and IND animals indicate that LAT may even be the most stressful of the three housing conditions. We therefore conclude that mice benefit most from social housing after surgery. If, however, social housing is not possible, individual housing appears to be a better option than separating mice by a grid partition.