As stated in the Guide for the Care and Use of Laboratory Animals (the Guide, p. 75):

"As a method of identification of small rodents, toe-clipping should be used only when no other individual identification method is feasible."

Therefore, the practice of cutting toes off rodents as a means of identification is unacceptable except with explicit approval of the ARC. When there is a research need to identify animals before ear notching or ear tags are feasible, marking the external skin with an indelible marker or administering a "tattoo" with a small injection of dye are effective methods that do not involve mutilation. If the principal investigator feels there is scientific justification for identifying animals by cutting toes, the ARC must be informed of the justification for the Committee’s review and approval.

If approved, toe-clipping may only be performed on altricial (no hair) neonates.


Approved 10/28/02; Revised 7/26/04, 4/16/10; Updated 1/18/11; Reviewed 3/14/16