Pain and Distress Categories

Policy 11 of the United States Department of Agriculture’s Animal Care Policies requires research facilities to have a mechanism in place for ensuring that animals are reported in the appropriate pain category on the annual report.  The Public Health Service’s Guide to the Care and Use of Laboratory Animals suggests scales of pain or invasiveness to aid in the preparation and review of protocols

The USDA has provided descriptions for each animal use category for USDA-regulated species on its annual report form.  In addition, the Texas A&M Institutional Animal Care and Use Committee has provided criteria for categorizing animal use for all vertebrate species.

These categories are assigned during pre-review of the AUP.

USDA Categories (USDA-regulated species only):

N/A       Animals not covered by the Animal Welfare Act (purpose bred mice and rats, birds, agricultural animals used for food and fiber work, reptiles, fish, amphibians, etc.)

B        Animals being bred, conditioned, or held for use in teaching, testing, experiments, research or surgery but not yet used for such purposes.

C     “Animals upon which teaching, research, experiments or tests were conducted involving no pain, distress, or use of pain-relieving drugs.”  This is interpreted as no more that momentary pain or distress such as that experienced during injections or brief restraint.

D       “Animals upon which experiments, teaching research, surgery, or tests were conducted involving accompanying pain or distress to the animals and for which appropriate anesthetic, analgesic, or tranquilizing drugs were used.”

E        “Animals upon which experiments, research, surgery, or tests were conducted involving accompanying pain or distress to the animals and for which the use of appropriate anesthetic, analgesic, or tranquilizing drugs would have adversely affected the procedures, results, or interpretation of the teaching, research experiments, surgery, or tests.” A written justification of the procedures producing pain or distress in these animals and the reasons such drugs were not used must be provided by the researcher.

TAMU IACUC Categories (all vertebrate species):

I          No pain – examples: Observational studies of animals in natural settings or tissues provided from other studies (no live animal work).

II       Minimal pain or distress – examples: Routine examination, injections, blood collection, approved methods of euthanasia that produce rapid unconsciousness, post mortem tissue collection.

III      Invasive studies performed on anesthetized animals; procedures involving mild discomfort which is short-lived or alleviated through treatment – examples: Survival surgery with minimal post-procedural discomfort, survival surgery with appropriate post-procedural analgesics, use of Freund’s complete adjuvant, acites production in mice, tumor implantation with early endpoints (no ulceration, noninvasive, no impact on general health and well-being).

IV        Procedures that inflict unrelieved pain or severe stress on conscious animals – examples: Toxicity studies, prolonged restraint, aversive conditioning, tumor burdens beyond those stated in III above, death as an experimental endpoint, clinical disease in which the course of the disease must be allowed to progress to a moribund state without intervention.