Premedication of rodents before gas anaesthesia for improved animal welfare and research

Gas anaesthesia is irritating to the airways and causes stress to the animals.

The stress can be reduced with sedative-analgesic premedication, yet millions of rodents are subjected to gas anaesthesia without premedication every year.

The goal of this project is to reduce stress and potential suffering caused by the use of gas anaesthesia without premedication in rodents.

The aim is to identify factors that contribute to stress and to evaluate dose dependent effects of premedication on behaviour, physiology and brain neurochemistry.

By establishing routines and premedication for reducing stress by gas anaesthesia, animal welfare is increased and negative effects on research reduced.

With a Design of Experiments (DoE) based strategy, in a first study the effects of gas volume displacement rate, gas temperature, time of day, habituation, type of gas, strain, and sex, on stress related behavior at induction and recovery will be investigated. During anaesthesia, physiological variables and plasma corticosterone levels are monitored.

The results of the first study are then used to optimize the design for study 2, in which dose related effects of premedication will be studied on the same parameters, as well as lasting effects on behavior and brain neurochemistry. The goal is to publish recommendations for premedication before gas anaesthesia in rodents.

This will benefit animal welfare and research quality alike. The three-year project is a collaboration between SLU and UU.