Broken Teeth, Infections, Chronic Diarrhea in Monkeys at UMass Prompt PETA Complaint to Feds

For Immediate Release:
May 7, 2025

Contact:
Tasgola Bruner 202-483-7382

Amherst, Mass. –

In a letter sent today, PETA urges the U.S. Department of Agriculture (USDA) to investigate apparent violations of the federal Animal Welfare Act in the laboratory of University of Massachusetts–Amherst (UMass) experimenter Agnès Lacreuse.

Animal care records obtained by PETA show that 10 marmosets confined and killed at UMass spent their final months suffering from injuries, gum infections, broken teeth, and chronic diarrhea, among other serious cardiovascular and metabolic health problems, with no indication that staff tried to treat the conditions or investigate the causes.

Many monkeys were described as “thin” or “very thin,” a possible indication of chronic wasting syndrome. This debilitating, poorly-understood condition includes muscle loss, weakness, and organ dysfunction and commonly affects marmosets imprisoned in laboratories.

Records also show that marmosets were injured because of improper handling or unsafe caging by staff or from fights with other monkeys. Several suffered a partial or complete detachment of a nail from the nail bed. This traumatic injury can be due to improper handling, bacterial or fungal infections, excessive grooming due to stress or discomfort, or metabolic bone disease. Marmosets rely on their nails for climbing and grasping, and the loss of nails can affect their mobility and cause considerable distress.

*A marmoset is imprisoned in Lacreuse’s laboratory. Image obtained through public records law by PETA.*

“UMass experimenters have a long history of animal welfare violations, and these latest records show they are either unwilling or unable to meet bare minimum federal standards,” says PETA neuroscientist Dr. Katherine Roe. “PETA urges the USDA to investigate promptly and take appropriate action to force UMass into compliance.”

PETA recently asked federal officials to investigate whether Lacreuse misused taxpayer money after she spent approximately $340,000 on a failed sleep deprivation experiment at the Wisconsin National Primate Research Center.

In nature, marmosets live in cooperative groups high up in the canopies of rainforests, where they groom each other, huddle affectionately, share food, and care for their babies.

PETA—whose motto reads, in part, that “animals are not ours to experiment on”—points out that Every Animal Is Someone and offers free Empathy Kits for people who need a lesson in kindness. For more information, please visit PETA.org or follow PETA on X, Facebook, or Instagram.