A federal inspection of the California National Primate Research Center at UC Davis flagged a string of ugly incidents among macaque monkeys, including fights that regulators say could have been avoided and one attack so severe it ended in an amputation. The March 4 review by the U.S. Department of Agriculture has animal-welfare advocates and university officials squaring off as federal regulators weigh their options.
What the inspection found
According to the inspection report, a staff member opened a door between enclosures that housed incompatible monkeys, and a 14-year-old male suffered lacerations serious enough to need stitches. In a separate case, inspectors said a weld failed, allowing a female macaque to escape and inflict severe injuries on another monkey, which ultimately led to amputations.
Regulators also cited the center for crowding two animals into an 8.6-square-foot enclosure, short of the required 10.3 square feet. Inspectors noted it was the first USDA report citing violations at the facility since July 2025. These findings were detailed by the Sacramento Bee.
Animal-welfare groups respond
People for the Ethical Treatment of Animals, after reviewing the inspection records, characterized the macaques' situation as one of "terror and suffering" and urged the federal government to close the primate center entirely. In its statement, PETA highlighted several incidents, including an account that two fingers were amputated after one monkey attacked a cagemate.
The group praised inspectors for issuing citations and argued that no incremental fixes will solve what it describes as systemic problems, stating that closure is the only acceptable outcome, according to PETA.
UC Davis' response and research context
UC Davis pushed back on calls for a shutdown. In a statement, university spokesperson Andy Fell said, "Animal research benefits human health and is strictly regulated. We strive to provide the best possible care to animals in our charge," and pointed to the school’s oversight procedures.
The primate center houses macaques used in research on HIV/SIV, Zika, aging and Alzheimer’s disease, and respiratory illnesses, according to its own materials. The university’s response was reported by the Sacramento Bee, and details about the center’s research portfolio are outlined by UC Davis' CNPRC.
Regulatory implications
The USDA’s Animal and Plant Health Inspection Service enforces the federal Animal Welfare Act and posts its inspection reports for covered research facilities. Inspectors can issue citations and official warnings and can require facilities to make specific corrections.
According to agency and university guidance, more serious or repeated problems can trigger civil penalties, as well as suspension or revocation of a facility’s license. Information about how inspections work and how penalties are handled is available from USDA APHIS and the UC Office of the President.
What comes next
UC Davis says it plans to correct the issues raised in the report while federal inspectors decide what, if any, follow-up enforcement is warranted. Animal-welfare advocates argue the latest citations are part of a broader pattern and are renewing calls to shutter the center. PETA reiterated that demand in a May 6 release.
For now, the process typically involves federal investigators tracking promised fixes and, if needed, returning for follow-up inspections before deciding whether to escalate to formal penalties.
