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NIH Seeks Input on Annual Reporting of Live Vertebrate Animal Numbers
NIH is committed to supporting rigorous and ethically conducted animal research that minimizes the number of animals needed to achieve scientifically valid results. Existing NIH policies and oversight processes require researchers to justify the species selected and the number of animals proposed for use in research. NIH also continues to encourage scientifically appropriate methods that reduce, replace, or refine laboratory animal use (see this statement from the NIH Director and this Nexus article). Transparent information about animal use can help support these broader efforts.
We already collect some information about institutional animal inventories. Currently, domestic institutions report an approximate average daily inventory by species as part of their Domestic Assurance, which is approved for a period of up to four years. This inventory is separate from the Annual Report submitted to the NIH Office of Laboratory Animal Welfare (OLAW), which currently does not require institutions to report annual animal numbers. NIH is now considering whether more comprehensive annual institutional reporting would be appropriate and feasible.
Through a recently released Request for Information (see NOT-OD-27-001 and this NIH press release), NIH seeks feedback on the feasibility, current capabilities, expected benefits, and expected burdens associated with annual reporting on the number of live, vertebrate animals subject to and defined by the Public Health Service Policy on Humane Care and Use of Laboratory Animals (PHS Policy). Comments must be submitted electronically here by December 21, 2026, and are especially encouraged from domestic and foreign institutions with an approved Animal Welfare Assurance.
This would bring reporting standards for laboratory animals not covered by the Animal Welfare Act (AWA) in line with existing reporting for AWA covered species, including animal numbers and U.S. Department of Agriculture (USDA) pain and distress categories. We are focused here on institutional, rather than project-specific, reporting of annual animal numbers.
Where NIH Seeks Input
As part of strengthening the rigor and transparency of NIH-supported research involving laboratory animals, NIH seeks input to better understand:
- Current practices: How proposed reporting requirements align with current institutional data collection, tracking, and reporting of animal numbers, including the software, systems, and existing internal or external processes used.
- Feasibility and implementation: Whether annual reporting is feasible and how long implementation would realistically take.
- Resources and burden: Staffing, systems, training, costs, and other direct or indirect administrative or financial burdens that annual reporting could create for assured organizations.
- Potential benefits, unanticipated consequences, and other considerations related to proposed changes to annual reporting requirements and making annual institutional reports publicly available.
- Scope of reporting: The feasibility of reporting cumulative annual numbers by species and USDA pain and distress categories for all live vertebrate animals covered by the PHS Policy. Note that the proposed reporting is separate from USDA requirements and would include all species covered by the definition of animal in the PHS Policy. For example, PHS reporting would include mice of the genus Mus, rats of the genus Rattus, fish, frogs, and other vertebrate species not covered under USDA reporting requirements.
The table below outlines current requirements and what changes are proposed.
| Category | Current | Proposed |
|---|---|---|
| Frequency | Domestic organizations provide an average daily inventory by species as part of the Domestic Animal Welfare Assurance, which is approved for up to four years. The Annual Report to OLAW does not currently require animal numbers. | Organizations with Domestic and Foreign Animal Welfare Assurances would report cumulative animal numbers annually. |
| What animal numbers would be reported to OLAW | Domestic Assurances include an average daily inventory by species for each animal facility (PHS Policy IV.A.1.h). Foreign Assurances do not currently require an average daily inventory. | Organizations with Domestic or Foreign Animal Welfare Assurances would report cumulative annual numbers by species. Estimates could be permitted in select instances, such as for fish. |
| Which animals would be included | The Domestic Assurance inventory includes live vertebrate animals subject to the PHS Policy. | Annual reporting would include all live vertebrate animal species defined by PHS Policy, including mice of the genus Mus, rats of the genus Rattus, fish, frogs, and other vertebrate species not covered by USDA reporting requirements. Animals used in field investigations are excluded. |
| Reporting pain and distress categories to OLAW | The Domestic Assurance inventory does not require animal numbers to be reported by USDA pain and distress category. | Annual animal numbers would be reported using USDA pain and distress categories established under the AWA regulations. |
| Annual OLAW reports publicly available online | No | Yes, annual reports by institution |
| Current USDA requirements? | USDA-registered research facilities submit annual reports to USDA documenting numbers of AWA-covered animals used or held for use in research, according to applicable USDA pain and distress categories. These reports are publicly available. | USDA's existing reporting requirements would not change. The proposed OLAW reporting would bring reporting for live vertebrate species not covered by the AWA more closely in line with existing reporting for AWA-covered species. |
The USDA (not NIH) administers the AWA regulations, which defines the pain and distress categories. See the additional resources below for existing USDA reporting requirements and other related information.
Where Do We Go Next?
Feedback on existing capabilities, implementation needs, potential benefits, and/or challenges will help NIH assess the feasibility of annual reporting and inform any future changes to current requirements. We look forward to your input as we move forward.
Additional Resources:
- NIH Grants and Funding: Assured Institutions Look Up Tool
- USDA Animal and Plant Health Inspection Services
Questions: [email protected]