Mbira, a 20-year-old lioness who has been a fixture of the Calgary Zoo since 1997, has been euthanized after veterinarians expressed their concerns with her deteriorating health.

A recent examination by the Calgary Zoo’s veterinary team determined Mbira’s kidneys had failed and cancerous changes to her spleen were beginning to spread to her abdomen.

The zoo said goodbye to Mbira on October 1.

Mbira arrived in Calgary from Denmark’s Aalborg Zoo in 1997. The lioness’ half-sister, 20-year-old Tisha, as well as two five-year-old male lions, Aslan and Baruti, remain under the care of the Calgary Zoo.

According to zoo officials, the average life expectancy for lions in captivity is less than 17 years.