— -- A rare white lion was euthanized this week after zoo keepers found he had age-related health issues.
The lion named Future, was one of two male African white lions at the Cincinnati Zoo and Botanical Garden. The two were loaned permanently to the Cincinnati Zoo & Botanical Garden by Siegfried and Roy in 1998.
At age 17, the rare lion's ability to move had been compromised according to zoo officials.
"Future's ambulatory condition had deteriorated and his quality of life was a significant concern. Euthanasia was the most humane course of action," said Mark Campbell, Cincinnati Zoo's director of animal health, in a statement.
The average life span for a white lion is 16.8 years, when living in a zoo, according to the Cincinnati Zoo & Botanical Garden.
"Future was a wonderful cat," said Future's zoo keeper, Michael, Land. "He was easy going as lions go and let (his brother) Sunshine do all the worrying. We will miss him."
"Future was our Brother; he will be sorely missed, especially since we are in the midst of the Holiday Season. We wish him a Magical Journey -- SARMOTI -- Siegfried & Roy," the two performers wrote.
White African lions are rare in the wild and in October the U.S. Fish and Wildlife Service proposed listing the African lion, including the white lions, as threatened under the Endangered Species Act.