Unfortunately, techniques for monitoring anesthetic depth vary somewhat with the agent used. A quiet animal that does not move when a painful stimulus is applied is the most certain indicator of adequate anesthesia, however, the zone between quiet and too quiet is very narrow in rodents. Maintaining body temperature is next in importance, as anesthetics induce hypothermia either directly or indirectly. It is easier to keep animals warm than warm them up. Warm water blankets or bottles provide supplementary warmth without being too hot.
Bubble wrap helps small rodents maintain body temperature.
These can be administered subcutaneously, intravenously or intraperitoneally. Any tissues exposed for long periods during surgery should be kept moist with these same warmed solutions. Some anesthetic agents, such as xylazine, will predispose an animal to volume depletion. Observation during postsurgical recovery is important. The animal, in or out of its cage, must be kept warm.