Individual housing of female mice: influence on postsurgical behaviour and recovery

Abstract

Individual housing of laboratory mice may increase vulnerability to surgical stress, and interfere with postsurgical recovery. To analyse the effect of housing conditions on recovery, pair-and single-housed female C57BL/6J mice underwent a minor laparotomy þ/2 analgesia, anaesthesia only or no treatment. Animals were monitored using non-invasive methods during the immediate postsurgical period to assess pain and general impairment. While no appearance or posture abnormalities were observed postexperiment, home cage behaviours were affected distinctly. Discriminant analysis identified self-grooming, locomotion, climbing and resting as mainly responsible for experimental group separation. Behavioural rhythmicity was disrupted, and behaviours related to wellbeing, such as nest building, climbing and burrowing, decreased. Behavioural pain signs (e.g. press) increased. Most behavioural alterations showed a gradation between treatments, e.g. burrowing latency ranged from an intermediate level following anaesthesia only and surgery with analgesia, to pronounced prolongation after surgery without analgesia. Significantly lower burrowing performance after surgery without analgesia in individuallyhoused animals indicates better recovery in pairs. Social interaction in pairs -an important component of normal behaviour (64%) and a potential indicator for direct social support -was nearly absent (0.3 -0.5%). While anaesthesia and surgery resulted in clear changes in behaviour, differences between housing conditions were minor. Hence, despite a tendency towards better recovery in pairs, we found no distinct negative effect of individual housing. In conclusion, both housing conditions are acceptable during the period immediately following minor surgery, though social housing is always preferable in female mice.

Assessment of postsurgical distress and pain in laboratory mice by nest complexity scoring

“…As observed already in previous studies, 12,13,29 anaesthesia alone had a marked impact on behaviour.…”

“…Even though the motivation to use the nest material was comparable under different conditions, it might be necessary to adapt the scoring system to other nest building material or housing conditions. As social housing is the preferred housing condition for mice and has been suggested to enhance postsurgical recovery in female mice, 15,29,35 further studies should focus on an adaption of the described assessment method to prevalent housing conditions like pair or group housing.…”

Buprenorphine via drinking water and combined oral-injection protocols for pain relief in mice

“…Jirkof et al (Jirkof, Cesarovic et al 2012) showed that mice undergoing a mild to moderate impact surgery like a oneside sham embryo transfer, even when not provided with analgesia, did not decrease their water intake post-surgery. Those animals that had been provided with analgesia, on the other hand, increased their water intake post-surgery, at least during the first six hours after surgery (day phase).…”

Endogenous α‐calcitonin‐gene‐related peptide promotes exercise‐induced, physiological heart hypertrophy in mice

“…All test trials started at 3 pm (lights on) and were digitally recorded for 24h with infrared sensitive cameras in the absence of a human observer. The recorded 24h video material was analysed using the ObserverXT® software (Noldus, Wageningen, Netherlands) (Jirkof et al, 2012).…”