THE UNIVERSITY OF TOLEDO
INSTITUTIONAL ANIMAL CARE AND USE COMMITTEE
SUBJECT: Use of Anesthesia when Tail Clipping for Genotyping
DATE: September 24, 2013
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The US Government Principles for the Utilization and Care of Vertebrate Animals Used
in Testing, Research, and Training states that “Procedures with animals that may cause
more than momentary or slight pain or distress should be performed with appropriate
sedation, analgesia, or anesthesia…”
The UT IACUC has determined that the following procedures must be implemented
when tail clipping rodents for the purpose of genotyping:
For rodents < 21 days of age, dip the tail in ice cold ethanol for appropriately 10-15
seconds. Clip appropriately 1-3 mm of the tail using sterile scissors or a scalpel. Apply
pressure as necessary to control bleeding.
Rodents > 21 days of age must be anesthetized prior to tail clipping. Isoflurane is the
recommended anesthesia as the animals recover quickly. The vaporizer and isoflurane
can be obtained from DLAR. Place the rodent in the chamber and introduce the
isoflurane at 2-5% in O2. Remove the animal from the chamber and clip the tail using
sterile scissors or a scalpel. Apply pressure as necessary to control bleeding.
The above procedures are considered to be Pain Category B. Failure to properly
anesthetize the tail or the animal results in a higher pain category (Category C) and is a
protocol violation. This is considered to be a serious matter that the institution may have
report to the Office of Laboratory Animal Welfare at the National Institutes of Health. All
research staff must follow the IACUC approved procedures for tail clipping rodents.
*This was in the form of a memo that was sent to all PI’s and research staff.