Protocol Modifications

The University of Mississippi Institutional Animal Care and Use Committee

Guidelines for Reporting Modifications to Protocols

Before they are instituted , modifications (significant or minor) to a protocol previously approved by the Institutional Animal Care and Use Committee (IACUC) must be reported to, reviewed by, and approved by the IACUC. Proposed modifications must fit with the objectives, purpose, or aims stated in the original protocol. If this requirement is not met, then the IACUC will require a new protocol.


The IACUC must review and approve all research study proposals (protocols) involving vertebrate animals in compliance with PHS Policy on Humane Care and Use of Laboratory Animals (PHS Policy II) and the Animal Welfare Act Regulations (AWAR §1.1 and §2.31). Principal investigators wanting to make any changes to an IACUC approved protocol must obtain IACUC approval in compliance with PHS Policy (IV, B, 7) and the AWAR (§2.31, c, 7).

Determination of Modifications

The IACUC has established the following guidelines to determine whether a requested modification is a minor or significant change to an active IACUC approved protocol. Contact the Attending Veterinarian (Dr. Harry Fyke, x5324) or the Chair of the IACUC (Mandy King, x5458) for guidance if in doubt whether a proposed change is “minor” or is “significant” from the point of view of animal welfare.

Minor Modification

The IACUC interprets “minor” changes to an animal study protocol as those that do not have a substantial impact on the health and well-being of research animals or that may decrease the potential for pain or distress (i.e. a refinement).

The following are changes that the IACUC regards as “minor” and requires only the AV and/or Chair’s approval:

  • Addition or deletion of personnel, other than the principal investigator;
  • Transfer of animals to another protocol where animals (same stock/strain) are already approved on that study;
  • Adding or changing the location where animal procedures are conducted;
  • Euthanasia procedures (from one AVMA approved method to another only);
  • Addition of animals (10% or less than the # approved for).

Significant Modification

The IACUC interprets “significant” changes to an animal study protocol as those that have the potential to substantially impact the health and well-being of research animals.

The following list is not exhaustive but is intended as a guide to the type of changes that the IACUC might regard as “significant,” thus requiring their review.

Change in:

  • Principal investigator of an animal study protocol.
  • Use of hazardous agents in animal procedures (this could mean chemical or biological or test compounds).
  • Procedures that will result in more than momentary or slight pain or distress.
  • Method of anesthesia, sedation or analgesia. (Minor changes may be approved by the Attending Veterinarian.)
  • Dose volume of experimental materials (increase), dose route (i.e., changing from I.P. to I.V. infusion), or dose frequency (increase).
  • Protocol that would require animals to be fed, housed or cared for in a way that is not standard for that species, or does not meet that species’ minimum requirements.
  • Significant food/water restrictions (not routine fasting).
  • Experimental protocol requiring more than momentary physical restraint of the conscious animal, e.g., use of other devices to physically restrain the subject while the experiment is in progress.
  • Protocol where death becomes the experimental end point. For purposes of this criterion, death is defined as natural death resulting from experimental conditions (rather than euthanasia at a time when a set of criteria recognized as the end point is met).
  • Protocol that would eliminate or restrict an animal’s access to veterinary care.
  • Protocol from non-surgery to surgery, from minor to major surgery, from non-survival to survival surgery, or from single to multiple survival surgery.
  • Method of euthanasia: e.g., (a) from a chemical or inhalant method to a physical method, (b) from any method to decapitation without anesthesia (c) from an AVMA recommended method to a method not specifically recommended.
  • Species.
  • Number of animals needed over original number approved, specifically an increase of more than:
    • Ten percent (10%) for projects approved for greater than 20 animals;
    • Three (3) animals for projects approved for 6 to 20 animals; or
    • One (1) animal for projects approved for 5 or fewer animals.

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