York University defends controversial experiments on live monkeys

Trigger warning: This article contains descriptions of animal experimentation and may be distressing to some readers.

York University is standing behind a controversial animal experimentation program, claiming that it has been cleared of animal mistreatment regarding studies carried out on a group of nine rhesus macaque monkeys.

The statement comes just over three months after international non-profit Last Chance for Animals (LCA) shared findings of a nine-month undercover investigation into animal testing at York University, which included shocking images of monkeys used for neuroscience research.

Graphic footage recorded between 2024 and 2025 by a whistleblower working with LCA showed macaque monkeys with visible brain implants and restraint collars, confined to empty metal cages and showing clear signs of distress.

LCA has since reported that it received a letter from York University on Aug. 12, 2026, in which the educational institution claimed the Canadian Council on Animal Care (CCAC) had cleared it of animal mistreatment violations.

LCA states that York declined meetings to discuss the investigation findings and stood behind its animal testing.

Chris DeRose, Founder and President of Last Chance for Animals, said that the organization is "outraged that York University is using the CCAC's alleged conclusion to shut the door on this matter."

"This does not make the suffering disappear. It does not change what our cameras captured. And it does not change what these macaques endured," said DeRose.

"LCA will keep putting pressure on York University, rallying supporters, and doing everything we can to get answers and to end cruel primate research."

"We are not giving up," DeRose added. "In fact, this is far from over. The public deserves to know why the CCAC made this decision and explain in detail how they determined this cruel treatment of animals is justified. We will continue to expose what happens to animals behind the closed doors of university laboratories and continue fighting for the York 9."

Among the investigation's findings, LCA claims that macaques are "living in small, barren cages who are unable to exhibit natural behaviors." LCA noted that the monkeys had "visible cranial implants, some of which were encrusted with blood."

The investigation claims most of the animals "were socially isolated," and all of the macaques "wore restraint collars 24/7."

Other troubling allegations include the animals being kept on water control, with one allegedly seen drinking its own urine.