ST. LOUIS — A beloved 29-year-old chimpanzee at the Saint Louis Zoo has died, the zoo announced Friday. The chimp named Mlinzi was euthanized after experiencing advanced heart failure.

She had received treatments for cardiac disease since 2014, but her condition worsened within the last 48 hours.

The zoo said caretakers and veterinarians decided that “euthanasia was the kindest and most humane action,” after assessing her long-term prognosis.

Mlinzi was just 2 years old when she came to the Saint Louis Zoo. She was part of a chimpanzee foster family that helped many young chimpanzees develop socialization skills with members of their species.

Her name derives from a Swahili word used to describe a protector and guardian. The zoo said it’s a role that Mlinzi took very seriously in her chimpanzee family.

“The animal care staff, the chimpanzee family, and all those who knew and loved Mlinzi are grieving her loss,” said Saint Louis Zoo curator of primates Heidi Hellmuth in a statement. “Our dedicated and experienced animal care and veterinary teams gave her the best care until her heart disease could no longer be managed.”

The zoo said spontaneous heart disease is a common health condition in adult great apes, both in the wild and in human care.