NHGRI ANIMAL CARE AND USE COMMITTEE (ACUC) GUIDELINES FOR EUTHANASIA OF RODENTS
(See also AVMA Guidelines for the Euthanasia of Animals)
Euthanasia of animals is an important consideration in all Animal Study Proposals
(ASP) approved by the NHGRI ACUC. The Principal Investigator and all investigators
on the protocol will be trained in the proper procedures for euthanasia and will be held
responsible for the correct implementation of these Guidelines. The NHGRI ACUC will
periodically review and update these Guidelines as the recommended procedures are
All methods of euthanasia of rodents must be in accordance with the 2000 Report
of the AVMA Panel on Euthanasia* and be approved by the NHGRI ACUC in the ASP.
Euthanasia must be performed by trained personnel using appropriate technique,
equipment, and agents.
Euthanasia should not be performed in the animal room and
chambers used for euthanasia must not be overcrowded.
Equipment used for euthanasia
should be sanitized before and after use. Equipment should also be sanitized between
groups of animals to remove residual pheromones, which may cause anxiety in
Whenever possible, animals should be euthanized in their home
cage in the animal facility procedure room. If rodents are removed from the animal
facility for euthanasia, you must have the proper equipment available in your laboratory
and your laboratory must be listed on the animal study proposal as an animal procedure
area. Your laboratory will also be inspected, at a minimum of semiannually, by the
NHGRI ACUC to ensure compliance with this Guideline.
To ensure humane and effective euthanasia individuals performing the techniques
below must be trained by the NHGRI APD or her designee prior to performing the
procedures. Upon completion of the euthanasia procedure death of the animal must be
confirmed. This can be accomplished by cervical dislocation, decapitation, or by creating
a bilateral pneumothorax. Once death is confirmed, the carcass is disposed of as defined
in the ASP.
1. Carbon dioxide is acceptable for euthanasia of rodents. Compressed CO2 gas in
cylinders is the only recommended source of CO2. Carbon dioxide generated from dry
ice is unacceptable. With an animal in the chamber, an optimal flow rate should
displace at least 20% of the chamber volume per minute. This requires knowing the
volume of your chamber and having a flow meter attached to the CO2 source. Once the
animal(s) is unconscious, the flow rate can be maximized until respiration ceases. Gas
flow should be maintained for at least 1 minute after apparent clinical death.
2. Inhalant anesthetics (e.g., halothane, isoflurane) can be used for euthanasia of
rodents. Halothane is the most effective inhalant anesthetic for euthanasia. Isoflurane is
also acceptable but euthanasia may be delayed as animals may hold their breath due to its
pungent odor. Inhalant anesthetics for euthanasia are best used in a closed receptacle
containing cotton or gauze soaked with the anesthetic. Care must be taken to prevent
direct contact of the animal with the liquid anesthetic. Anesthetic can also be introduced
from a vaporizer but this results in a longer induction time. Inhalant anesthetics must be
used with a down-draft table, biosafety cabinet vented to the outside (BSCIIB2), or in a
chemical fume hood
1. Barbiturate anesthetics, injected intraperitoneally (IP) in rodents, produces rapid,
smooth, and humane euthanasia. Barbiturates are controlled substances and must be
procured through your Controlled Substances Officer.** The user of controlled
substances is accountable for strict record-keeping procedures.
1. Cervical dislocation without prior narcotization or anesthesia is to be used only
when scientifically justified by the user and approved by the NHGRI ACUC.
2. Decapitation of post-natal rodents (>14 days of age) without prior narcotization or
anesthesia is conditionally acceptable, if performed correctly. It is to be used only when
scientifically justified by the user and approved by the NHGRI ACUC. The equipment
used to perform decapitation should be maintained in good working order and serviced
on a regular basis to ensure sharpness of blades.
1. Euthanasia of neonates and fetuses must be in accordance with the NIH Animal
Research Advisory Committee (ARAC) Guidelines for the Euthanasia of Mouse and Rat
Approved by the NHGRI ACUC 5/15/01
** For more information see http://www3.od.nih.gov/oma/manualchapters/management/1345/main.html
Sources: US National Institutes of Health