Refining cage change routines: comparison of cardiovascular responses to three different ways of cage change in rats

Cage change is one of the unavoidable routines in laboratory rodent care. However, cage change disrupts the rodents’ olfactory environment and can evoke stress reactions. In this study, the short-term cardiovascular responses to three different cage change procedures were compared with telemetric monitoring. These procedures were: placing the rats into a new, clean cage (NEW), transferring the old cage lid into the clean cage (LID) and transferring an enrichment object into the clean cage (ENR) with the animals. Seven outbred rats (four Hsd:Sprague-Dawley and three HsdBrlHan:WIST) were instrumented with telemetric transmitters. The reactions were recorded during the 24 h following the cage change procedures. All cage change procedures (and also simple handling) caused elevated heart rate and mean arterial pressure levels for up to 5 h after the procedure, with the largest effect seen during the first hour. The reactions observed after cage change were significantly (P < 0.05) greater than those observed a...