The anesthetic mixture of ketamine and xylazine works well in mice. The
margin of safety and rapid recovery are positive features. Isoflurane is also an excellent anesthetic but the cost of the equipment necessary to safely use this volatile
anesthetic is high. The surgeon should be careful to work in a vented hood to reduce exposure during procedures.
Body Temperature
The high metabolic rate and high surface-to-volume ratio of mice means
that they lose heat very quickly. It is therefore imperative to avoid anesthetics such as barbiturates, which alter the animal's ability to maintain core temperature.
Similarly, the animal should be warmed during operative procedures which open a body cavity and expose even greater surface area to ambient temperatures for heat loss.
Body temperature should be monitored during heating to avoid increasing body temperature above 38ºC.
Special Equipment Needs
Microscope
Equipment needs for mouse surgery vary with the procedures undertaken.
Vascular catheterizations are much easier to perform using a stereo microscope. Try the microscope in the application you intend to use it in before you purchase it.
Working distances and heights vary a great deal between microscopes and not all configurations are appropriate for an individual. Very good surgical loupes can be used
for some procedures but these require adaptation by the user. The focal length is fixed and images are brought into focus by moving one's head. This movement can be
distracting until one gets used to it.
Respirator
A good rodent respirator is essential for performing mouse
thoracotomies. The respirator should provide pressure limits to avoid over infusion of the lungs and should be adjustable (inflation rates, respiratory rates, PEEP),
Kent Scientific is a good source for respirators.
Surgical Instruments
Finally, surgical instruments for mice are a little smaller, a lot
more expensive and very delicate. A common mistake made by investigators is to use instruments that are too big or really cheap. Good advice is to look at a lot of
instruments before buying (at scientific conventions), select instruments carefully putting need first, and take extra special care of your instruments once purchased.
They should always be cleaned, dried and oiled (If they have moving parts) immediately after use. They should be stored in a safe place. They should not be loaned to
others. Good instruments will last many years and are an investment. They allow you to do the work you are trying to perform and pay for themselves in time saved and
years of service.
