Are non-USDA regulated species ever required to be classified in a pain/distress category?

Non-USDA regulated species are not required to be classified in a pain/distress category under the guidelines set by the Animal Welfare Act (AWA) as administered by the USDA. The AWA primarily covers species such as dogs, cats, primates, guinea pigs, and rabbits, while many other types of animals used in research, like mice and rats, are not included in this regulation. Therefore, investigations involving these non-USDA regulated species do not have the same mandatory requirements for pain and distress categorization.

This means that researchers still have an ethical responsibility to minimize pain and distress for any animal used, but formal classification into a pain/distress category is not mandated for these species. Understanding this helps ensure compliance with broader animal welfare principles, even in the absence of specific regulatory requirements.