Administering Anesthesia to Mice, Rats, and Hamsters.

Anesthesia is used to sedate animals during injections or during operations where unexpected or rapid movements would endanger the animal. Inhalant anesthetics are often the most appropriate choice to achieve anesthesia that meets the clinical and humane needs without interfering with the scientific goals of the research protocol. Isoflurane (i.e., halogenated ether)-the preferred inhalant anesthetic for small animals-is administered either by placing the animals in a closed container permeated with a mixture of isoflurane and oxygen vapor, or by using a mask (for larger animals). The depth of anesthesia is easy to assess and to control. Animals sedated by isoflurane can be handled for injections or simple operations.