Ether is extremely flammable and not acceptable unless used with adequate protection against the risk of explosion. Although not required, the use of sedation or anesthesia prior to euthanasia is encouraged. If sedation or anesthesia prior to cervical dislocation is not used the investigator must provide scientific justification for its exclusion. In the case of mice and small rats, the animal is held by its tail and placed on a surface that it can grip, then it will stretch itself out so that a pencil or similar object can be placed firmly across the back of the neck. A sharp pull on the base of the tail will then dislocate the neck.
Decapitation is acceptable for rodents, rabbits and birds, and other animals of similar size.
This requires special equipment and is aesthetically unacceptable to many. Because of electroencephalographic evidence suggesting continued cortical activity after decapitation the Report of the American Veterinary Medical Association Panel on Euthanasia recommends that animals be anesthetized when decapitated or that the investigator provide scientific justification for the use of this technique without anesthesia or sedation. While the use of anesthetics prior to decapitation is preferred, the scientific justification for decapitation may precludes their use. In lieu of the use of anesthetics, prior recommendations have required the immediate placement of the decapitated head into liquid nitrogen. This is still an acceptable alternative however it is not required in part because of the human safety risk.