SMPH Policy Number: 3

Policy Title: Pain, Distress, or Death as Experimental End-Points and Euthanasia


Unalleviated Pain and Distress:

Some studies may cause potential or actual pain (severe or chronic) or distress that cannot be relieved by medication or other methods. In such cases, the animals must be euthanized at the end or, if appropriate, during the procedure. Deviations from this policy may be acceptable if there is a convincing, specific, and detailed scientific justification for using pain, distress, or death as end-points in the study. The justification should explain how applying less severe or extreme end-points would jeopardize the goals of the research. The methods of euthanasia must be consistent with the recommendations of the AVMA Panel on Euthanasia.

Death as an End-point:

Some studies require the use of death as an end-point (ex. toxicity studies, vaccine efficacy studies, some types of cancer research). In such cases convincing, specific, and detailed scientific justification must be established for why the use of a less severe scoring criteria and/ or end-point would severely jeopardize the goals of the research.

Role of the Investigator:

  1. The principal investigator is responsible for ensuring appropriate monitoring animals and ensuring that the end-points specified in the approved Animal Care and Use Protocol are applied.
  2. The protocol must specify objective criteria, such as degree of a physical or behavioral deficit or tumor size, etc., that will enable a prompt decision regarding initiation of euthanasia to be made. Development of a multifaceted criteria or scoring scale is encouraged to allow the collection of scientifically relevant data while allowing for relief of pain and distress of research animals in the shortest amount of time.
  3. The method of euthanasia must be described in the protocol. The use of physical methods, such as cervical dislocation or decapitation, on animals that are not sedated or anesthetized requires a scientific justification for withholding sedatives or anesthetics.

Role of the Veterinary Staff and Laboratory Animal Resources (LAR):

In addition to the principal investigator monitoring animals that might develop severe chronic pain, distress, or die, the LAR staff also will monitor these animals during performance of their daily animal husbandry duties. Animals in severe pain or distress, sick, injured or requiring immediate attention will be brought to the attention of the investigator and veterinary staff who will reach agreement on treatment. If the veterinarian judges that the animal needs immediate and urgent attention, the veterinarian has the authority to implement appropriate intervention, which may include euthanasia.

Animal Care and Use Committee (ACUC) Oversight:

The ACUC has ultimate responsibility for ensuring that pain and distress in research animals is limited to that which is necessary in the course of approved experimentation. This includes review and approval of methods and agents used for euthanasia of animals as well as experimental end-points. Committee decisions in this regard will be based on regulatory requirements as well as advice from the veterinary staff and the investigators. The ACUC will periodically review (at least every 3 years) all protocols. The review will specifically assess methods and agents being used and deviations (if any) from this policy.


Approved: April 1997
Amended: July 2009