Statement From the Physicians Committee for Responsible Medicine on NIH Plan to Accurately Count Animals in Labs

The Physicians Committee for Responsible Medicine is celebrating the announcement today by the National Institutes of Health that the agency is considering a plan to accurately count vertebrate animals used in agency-funded research facilities and publicly report that information. For years, the Physicians Committee, a nonprofit research ethics group, has led the effort to establish this kind of national reporting system.

The NIH today announced a request for information regarding the tracking and reporting of “cumulative annual numbers by species, which may be estimated in select instances (e.g. fish, if necessary), and would include all live vertebrate animal species as defined by the PHS Policy such as mice of the Genus Mus, rats of the genus Rattus, fish, frogs, etc.” Currently, more than 95% of animals used in NIH-funded labs are excluded from accurate reporting requirements.

“This is a potentially historic change,” said Ryan Merkley, director of research advocacy at the Physicians Committee. “Research is shifting away from a reliance on animals and toward human-based methods, but we currently have no idea how many animals are used by taxpayer-funded labs. Today’s announcement would fix that decades-old problem, but the NIH needs to follow through on this plan.”

The Physicians Committee points out that the European Union, United Kingdom, and other governments collect and disclose to the public detailed information about the number of animals used in experiments. In comparison, the NIH, which annually awards about $20 billion worth of grants involving animals to more than 800 labs, currently collects only crude estimates every four years from those labs.

Physicians Committee staff were the first ever to obtain and compile the crude estimates filed with the NIH, a project they presented in 2023 at the 12^th World Congress on Alternatives and Animal Use in the Life Sciences. The data revealed that, at any given time, almost 20 million vertebrate animals were held or used in laboratories funded by the NIH and other agencies. But that figure is likely the tip of the iceberg, with at least one prominent expert suggesting the true number is more than 110 million animals used each year.

Since 2021, the Physicians Committee has lobbied Congress to fix this reporting problem. In 2025, the group worked with Reps. Nicole Malliotakis (R-N.Y.), Don Davis (D-N.C.), and Jen Kiggans (R-Va.), who introduced the Federal Animal Research Accountability Act (H.R. 3295). Under that bill, a facility that receives funding from the NIH or another agency within the U.S. Public Health Service would annually file a short form with the NIH listing the number of animals used in the previous fiscal year, sorted by species and level of pain and distress. The NIH would then post those forms online for the public to access. Today’s announcement by the agency closely mirrors that legislation.

In September 2025, the Physicians Committee hosted a congressional briefing on this issue that featured NIH acting deputy director Nicole Kleinstreuer, PhD, and Rep. Davis.

In January 2026, Merkley sent a memo to NIH Director Jayanta Bhattacharya, MD, PhD, titled “Progress Through Transparency: Counting Animals in PHS-Funded Facilities.” The document pointed out that large research facilities routinely use software to track animal numbers. Public records obtained by the Physicians Committee reveal that the University of California, San Francisco; the University of California, Los Angeles; and the University of Colorado Denver compile internal annual reports identical to what the NIH is now proposing, but those reports have never been provided to the agency. The University of Washington proactively publishes its data online.