This policy refers to mice and rats 15 days of age and older. For euthanasia of fetuses and neonates, please refer to the ARC Policy on Euthanasia of Fetuses and Neonates – Mice and Rats.
The recommended methods for adult rodent euthanasia are anesthetic overdose or CO2 asphyxiation. When physical methods of euthanasia are used, they must be conducted in accordance with the AVMA Guidelines for the Euthanasia of Animals. Specifically, physical methods of euthanasia must be skillfully executed to ensure a quick and humane death, because failure to do so can cause substantial suffering. Personnel using physical methods must be well-trained and proficient for each type of physical method performed to ensure euthanasia is conducted appropriately.
Decapitation provides a means to recover tissues and body fluids that are chemically uncontaminated. There is an inherent danger in the use of a guillotine and personnel should take adequate precautions for their own safety. Recommendations of the AVMA Guidelines for the Euthanasia of Animals state that “The equipment used to perform decapitation must be maintained in good working order and serviced on a regular basis to ensure sharpness of blades. The use of plastic cones to restrain animals appears to reduce distress from handling, minimizes the chance of injury to personnel, and improves positioning of the animal.”
Thus, the ARC requires the following: 1) after each use, the decapitation equipment should be wiped clean of any biological fluids to prevent buildup of potential corrosion; 2) after cleaning, a few drops of light machine oil (e.g., 3 in 1) should be applied to blade surfaces and blade channels, and the blades run together several times to spread the oil evenly over all moving surfaces; 3) blades should be replaced or sharpened regularly depending upon frequency of use.
Cervical dislocation is a method that induces rapid loss of consciousness and does not chemically contaminate tissue. Consistent with the AVMA Guidelines for the Euthanasia of Animals, cervical dislocation may not be performed on rats weighing greater than 200g, since the large physical mass in the cervical region makes manual cervical dislocation physically more difficult. Decapitation should be used if a physical method is required for rats weighing more than 200g.
Training of Personnel
The AVMA Guidelines for the Euthanasia of Animals stipulate that personnel responsible for performing euthanasia by physical methods must be properly trained and proficient in carrying out these techniques. Therefore, personnel who will perform decapitation or cervical dislocation without prior anesthesia must be identified in the approved research protocol, and the principal investigator must include a plan for training of personnel who are not experienced in these techniques prior to performing euthanasia. Whenever possible, training personnel in physical methods should initially include the use of anesthetized animals, or carcasses of animals euthanized by non-physical methods, before practicing on an unanesthetized animal. DLAM veterinary staff are available for consultation and training in these methods when needed.
Euthanasia of Animals in Housing Rooms
Use of a physical method of euthanasia is often accompanied by ultrasonic vocalizations and pheromones released during handling/restraint prior to euthanasia, and by odors released into the blood after euthanasia, any of which may serve as stress cues to other animals. Therefore, euthanasia involving a physical method must be performed outside the housing room. If a number of animals are being euthanized by a physical method, they should be held in a location that is removed from the area where the euthanasia is being performed.
Approved 7/26/04; Revised 6/14/10, 11/14/16
Replaces ARC Policy on Euthanasia of Rodents by Decapitation 9/24/01