Use of anesthetics/analgesics is required when procedures are reasonably considered to produce pain or distress. These procedures and the plan for alleviation of pain/distress must be identified in the Animal Care and Use Protocol. The Attending Veterinarian can advise you on the selection of appropriate anesthetics/analgesics. See the following for more information. http://www.southalabama.edu/researchcompliance/pdf/pain_in_animals_ILAR.pdf