Middlebury College has permanently banned one of its researchers from entering the campus vivarium following the botched euthanasia of a test rat during federally funded research.
The incident has prompted fresh criticism of the program, which faced a slew of compliance issues several years ago.
The researcher — whom college officials have refused to identify — was performing a standard method of euthanasia for rodents, which involves using carbon dioxide gas to render the rat unconscious, then slicing into its chest to cause the animal’s lungs to collapse.
The secondary surgical step ensures that the animal does not recover from the comatose state induced by the gas, which in some cases is not fatal.
During the incident in question, a male albino rat moved and showed “clear signs of pain” when the researcher began the process of cutting into its chest, a witness reported, according to a written report prepared by a college compliance official.
The witness intervened, and the researcher placed the rat back into the carbon-dioxide chamber, the report states.
The rats were part of a research study led by Professor of Biology Mark Spritzer that examines how testosterone levels affect the brain with age. It’s funded by a $387,000 grant from the National Institutes of Health.
Middlebury College officials reported the incident to the federal agency, as required, and they decided to ban the researcher from using the animal lab, according to the report.
Stop Animal Exploitation NOW! — a national group that opposes lab experimentation using live animals — obtained information about the case through a public records request and publicized it last week.
The college cited past incidents of noncompliance as part of its decision to “permanently revoke” the researcher’s “vivarium privileges.”
The report does not specify which prior incidents officials had in mind, but Middlebury disclosed a slew of problems related to rat research in 2024. The deficiencies included rats whose sutures were not removed and instances in which rats did not have water bottles in their cages.
To resolve those 2024 issues, the college required more training for student researchers and daily inspections of the vivarium conditions by the principal investigator.
Associate Dean of the Sciences Richard Bunt said that the project’s principal investigator is the researcher who has now been banned, but he refused to confirm their identity.
Spritzer is listed in a federal database as the principal investigator for the NIH-funded research. He spoke to the Middlebury Campus student newspaper about the project in 2025, before the most recent compliance issue arose.
Reached by email, Spritzer did not clarify his role in the incident, except to say the accident involved a rat in one of his “research protocols.”
“Our response to the accident was swift and thorough,” Spritzer said, adding that “one researcher is no longer conducting work with live animals.”
Spritzer said the NIH accepted Middlebury’s corrective plan, which included reassigning responsibilities on the grant. An NIH spokesperson declined to comment on the case.
The animal rights group says the feds should do more. The group’s executive director, Michael A. Budkie, wrote a letter to NIH Director Jay Bhattacharya asking the agency to ban the researcher from future federal grants and to demand that Middlebury refund the $387,000 grant.
“The manner in which it was performed was an embarrassment to the entire scientific community,” Budkie wrote.
In a statement, Middlebury College said it takes animal welfare seriously and is “committed to the highest standards of care.”
