CHATTANOOGA, TN (WRCB) -- The Chattanooga Zoo announced Monday that they had to reluctantly euthanize "Josie" the chimpanzee on Sunday, December 30.

The difficult decision to euthanize was made by Zoo Veterinary staff after weeks of rapid deterioration and weight loss by the 37-year old female chimp.

Recently, Zoo staff noticed Josie's increasingly impaired mobility and rapid weight loss. After a thorough examination by Zoo Veterinary staff and the University of Tennessee's School of Veterinary Medicine, it was determined that the chimpanzee was not going to get better only worse.

"It really came down to a quality of life issue for Josie," says Zoo Executive Director, Darde Long. "It would have been selfish on our part to keep her alive in her current state with such a poor prognosis from both our Veterinarian and the UT Veterinary School."

Josie came to live at the Chattanooga Zoo from the Fort Worth Zoo in 2001 as part of the Association of Zoo and Aquarium's (AZA) Species Survival Plan.

She is survived by two female and one male chimpanzee that were part of the same group from Fort Worth.