For experiments involving the use of electrical stimulation, the ARC has developed the following guidelines for pain categorization of animals.


Guidelines for Single Electrical Stimulations

In order to list animals in Pain Category C (momentary or no pain/distress), the product of current in milliamps x duration in seconds from a constant current AC source must not exceed 5 millicoulombs for a single electrical stimulation. Animals must be listed in Pain Category E (pain/distress cannot be relieved by use of anesthetics, analgesics, or tranquilizers, as the use of these agents would interfere with the experimental design) if this limit is exceeded. Please note that scientific justification must be provided for exceeding 5 millicoulombs for a single stimulation.

Guidelines for Repeated Electrical Stimulations

As a general guideline, animals must be listed in Pain Category E, with appropriate scientific justification provided as part of the research protocol, if more than 60 millicoulombs will be applied over the course of the animal’s lifetime. However, the ARC will use this threshold in combination with other factors in evaluating the most appropriate pain category for the animals. For example, animals may be placed in Pain Category E if the intent of the study is to create a model of persistent psychological distress or to induce localized tissue damage using lesser amounts of shock. Alternatively, animals that are allowed to voluntarily receive shock in order to gain access to an appetitive reward may be placed in Pain Category C even if the animal is permitted to self-administer a higher amount of shock.


Generally, animals must be listed in Pain Category D (pain/distress relieved by use of appropriate anesthetics, analgesics, tranquilizers or by euthanasia) due to the application of anesthesia. However, Pain Category E is appropriate if the procedures are expected to cause tissue damage resulting in pain that cannot be relieved upon recovery. If Pain Category E is found to be appropriate, the investigator must provide scientific justification for (1) the total amount of shock to be applied and (2) withholding analgesia or other pain-relieving drugs following recovery from anesthesia.

Approved 6/11/01; Revised 1/11/10