Painful Procedures List

Painful Procedures used in Research Laboratory Animals

The IACUC has reviewed commonly performed procedures and has classified those procedures into pain categories.  This should be considered a starting point.

The IACUC actively reviews all commonly performed procedures and, for the purposes of understanding how these procedures can impact animal well-being, these procedures are assigned pain categories analogous to the definitions set forth by the USDA.  Because of the unique nature of science, each protocol is considered independently and the scope of potentially painful procedures are considered in the context of each protocol.  The specific pain category for any procedure may be changed by the IACUC as it best reflects the proposed work and expected well-being in that protocol.

Pain Category B (breeding and housing)

  • Breeding only
  • Housing only

Pain Category C (momentary pain or distress)

  • Alert animals (behavioral observation or brief restraint)
  • Anesthetize and release for non-invasive procedures (e.g., imaging, bandage change)
  • Change in environmental parameters (e.g., diet, light cycle, room temperature if within thermoneutral zone)
  • Chemical carcinogen use (e.g., BrdU)
  • Euthanasia with or without tissue/organ harvest
  • Food restriction that results in weight loss of <20% of normal age-matched controls
  • Gavage
  • Irradiation (sublethal or with reconstitution)
  • Non-surgical collection of body fluids (blood, urine, etc.) unless otherwise categorized
  • Radioisotope use
  • Simple injections (IP, IV, SubQ, etc.)
  • Tail biopsy for genotyping prior to or at weaning
  • Use as a parasitic host

Pain Category D (more than momentary pain or distress for which appropriate anesthetic, analgesic, or tranquilizing drugs will be used)

  • Antibody production:  polyclonal (non-ascites, no footpad injections)
  • Burns
  • Diagnostic procedures  (e.g, laparoscopy, needle biopsy)
  • Electric shock with escape
  • Introduction of illness (including the administration of toxins, microbiological agents, clincal transgenic phenotypes) with pain relief
  • Lavage
  • Non-survival surgery
  • Physical trauma
  • Survival surgery
  • Tail biopsy for genotyping on post-weaning animals
  • Toxic substances use (e.g., streptozotocin, MPTP, cisplatin, doxycyline)
  • Transgenic mouse production (embryo manipulations to produce novel strains, etc.)
  • Tumor induction or implantation without metastasis
  • Exposure of skin to UV light to induce sunburn with pain relief
  • Exposure of blood vessels for catheterization
  • Exsanguination or transcardial perfusion under anesthesia

Pain Category E (more than momentary pain or distress for which appropriate anesthetic, analgesic, or tranquilizing agents are not used)

  • Antibody production:  ascites
  • Death as an Endpoint or lethal dose studies
  • Euthanasia by procedures not approved by AVMA Guidelines
  • Exposure to extreme environmental temperatures
  • Food restriction that results in weight loss of >20% of normal age-matched controls
  • Footpad injections (antibody production or microorganism)
  • Forced exercise
  • Genetically engineered animals with phenotype that causes pain or distress that will not or cannot be alleviated
  • Housing outside thermoneutral zone
  • Induction of arthritis with prolonged pain and discomfort
  • Induction of illness (including the administration of toxins, LPS, microbiological agents without pain relief)
  • Noxious stimuli from which there is no escape, including electric shock
  • Ocular or skin irritancy tests
  • Pain study
  • Paralysis
  • Total body irradiation (lethal or without reconstitution)
  • Tumor production or implantation with metastasis
  • Unusual or prolonged restraint (e.g., pie chamber, chair – 30 minutes or more in a conscious animal)
  • Use of housing outside thermoneutral zone
  • Water deprivation beyond that which is necessary for ordinary pre-surgical preparation
  • Withholding of post-operative analgesia for any surgical procedure for which analgesia is typically given