DIRECTIONS: Review the following material. Keep copies of guidelines with applicable protocols. You may find it helpful to post a copy of these guidelines in your laboratory. Questions should be forwarded to the APLAC office (723-4550).
TRAINING: Training in these techniques and the humane treatment of laboratory animals during the procedures is taught by the Veterinary Service Center (VSC) staff. All new personnel who will be performing these techniques should contact VSC staff for training (725-9901).
I. Background
These guidelines have been written to assist Protocol Directors (PD) in complying with American Veterinary Medical Association (AVMA) recommendations as well as to apprise them of effective techniques for rodent euthanasia. The APLAC is specifically charged with reviewing the methods of euthanasia for each research protocol to assure compliance with the recommendations contained in the AVMA Guidelines on Euthanasia, June 2007 (Formerly Report of the AVMA Panel on Euthanasia). Since physical methods of euthanasia (such as cervical dislocation) require the most skill to perform and are most likely to be affected by human error, the AVMA Guidelines recommends that such methods are used only when alternative methods are not appropriate.
II. Acceptable Use
This guideline recommends the use of cervical dislocation only when scientifically justified and approved by the APLAC. Methods deviating from these recommendations must be "justified for scientific reasons in writing by the investigator." Justifications must be included in the protocol and will be evaluated on a case-by-case basis. Justifications must be evidence-based (e.g., cited references, data from a pilot study, or historical knowledge within the laboratory). If approved, the APLAC may conduct periodic review of persons performing this technique to ensure compliance and verify proficiency.
Cervical dislocation on conscious rodents is discouraged based on animal welfare concerns. Use of cervical dislocation to euthanize mice and rats with body weights <200g by trained personnel is appropriate (upon APLAC approval) if animals are sedated or anesthetized using drugs or carbon dioxide prior to cervical dislocation, or as a secondary method to confirm death.
III. Training Requirements
The APLAC reviews all protocols using physical techniques to assure that personnel performing the procedures are appropriately trained. The primary responsibility for establishing and monitoring this training lies with the PD. Before using physical methods, inexperienced persons should be trained by experienced persons and should practice on carcasses or anesthetized animals to be euthanized until they are proficient in performing the method properly and humanely. The staff of the Veterinary Service Center (VSC; 723-3876) is available upon request to provide this training to personnel listed on approved protocols.
IV. Method
Before using the technique of cervical dislocation, it should be practiced on carcasses or anaesthetized mice until the operator is competent.
- Restrain the rodent in a normal standing position on a firm, flat surface and grasp the tail with one hand.
- Place a rod-shaped instrument or the thumb and first finger of the other hand against the back of the neck at the base of the skull.
- To produce the dislocation, quickly push forward and down with the hand or object restraining the head while pulling backward with the hand holding the tail.
Performing the procedure on a surface that the animal can grip may make it easier to gain access to the base of the skull because rodents often stretch themselves forward when held by the tail. The effectiveness of dislocation can be verified by separation of cervical vertebrae. When the spinal cord is severed, a 2-4 mm space will be palpable between the occipital condyles and the first cervical vertebra. Check closely to confirm respiratory arrest, and when possible verify, by palpation, that there is no heart beat.
V. References
AVMA Guidelines on Euthanasia, June 2007
Vanderwolf CH, Buzak DP, Cain RK, et al. Neocortical and hippocampal electrical activity following decapitation in the rat. Brain Res 1988; 451:340–344.
Contact: APLAC Administrator
Last updated: July 2009
