People for the Ethical Treatment of Animals is calling for University of Colorado Boulder leaders to do away with the tradition of Ralphie, the live buffalo mascot whose wild runs kick off home football games.

In a letter addressed to CU system President Mark Kennedy and posted online Wednesday, the animal rights group described the use of live animal mascots as “a recipe for disaster.”

“Even if animals aren’t physically harmed, it’s hard to imagine that they enjoy being paraded before raucous crowds, entirely out of their element, and treated as if they were toys rather than living, feeling beings with interests, personalities and needs of their own,” wrote Marta Holmberg, senior director of youth programs for PETA. “Being forced into a stadium full of bright lights, exuberantly screaming fans and loud noises is stressful — and can be terrifying — for animals who have no idea what’s going on or why.”

Kennedy has not received a letter from PETA, according to system spokesman Ken McConnellogue.

CU Boulder announced the retirement of Ralphie V on Nov. 12 and is currently searching for her successor. The university has no plans to stop the Ralphie tradition, said spokesman Ryan Huff.

In a statement, Ralphie manager John Graves said Ralphie V had a happy and safe tenure as CU Boulder’s mascot.

“No one cares more about Ralphie’s well-being than the handlers and me,” Graves said. “From the time Ralphie V was 6 months old, I’ve been by her side nearly every day for the past 13 years. I am confident she is happy and healthy. That will continue in the years ahead at her ranch alongside the next Ralphie.”

CU Boulder has used a live animal mascot since 1967, Graves said, which includes a track record of safety and plenty of precautions — including the recent decision to retire Ralphie V after she started becoming less responsive to cues from her handlers.

“Ralphie enjoys the spotlight as the queen of our campus and she gets better care than most buffalo,” Graves said. “We are now in the process of finding Ralphie VI, and that will require months of training for her and the handlers to ensure we continue this tradition in a safe and healthy way.”

PETA has a history of protesting any live animal mascot, including the University of Georgia’s bulldog, Uga, and Louisiana State University’s Bengal-Siberian tiger, Mike.

Boulder resident Jennifer Rodehaver said ending the Ralphie program was her first thought after hearing Ralphie V was retiring.

“The whole idea of using animals for entertainment is really abhorrent to me,” she said. “It has to do with a sort of arrogance humans have that they can own another creature and train it to do tricks or confine it, to take away that animal’s rights to just be, to exist as their masters of their own destiny.”