LITTLE ROCK, Ark. (KTHV) – Sidney, the Little Rock Zoo’s 22-year-old lioness, was euthanized Sunday morning after a corneal graft on her eye deteriorated.

Sidney originally had preventative surgery on her eyes in January, when she was diagnosed with corneal degeneration, a thinning of the cornea that also occurs in humans as they age, said Sarah Kline, the zoo’s veterinarian.

In September, Kline and a veterinary ophthalmologist repaired a corneal perforation or rupture on Sidney’s left eye.

“At that time we realized she also had bloodwork indicating progressive kidney and liver disease,” Kline said. “This is a common finding in both domestic and exotic older cats.

Kline said that by the end of last week, Sidney’s eye was looking abnormal.

“We would’ve had to remove the eye. Due to her advanced age, the kidney disease, and the liver disease, the decision was made to euthanize rather than put her through another surgery,” Kline said.

Born in 1994, Sidney came to the Little Rock Zoo in 2000 from Dickerson Park Zoo with female companion, Nyla. Both were former pets that were donated to the Dickerson Park Zoo by a private owner. They were then donated to the Little Rock Zoo by Dickerson Park. Both had declawed front paws and filed-down incisors, a common practice of the pet trade.

Debbie Thompson, curator of carnivores at the Little Rock Zoo, said she expects another female to join 10-year-old Bakari in the near future. Bakari came to the Little Rock Zoo in 2009. He’s still of prime breeding age, but couldn’t sire cubs with Nyla or Sidney because they were spayed due to their undocumented backgrounds in the pet trade.

Since lions are endangered species, breeding is closely managed by the Association of Zoos and Aquariums’ Species Survival Plan to ensure genetic diversity. The plan makes breeding and transfer recommendations and helps participating zoos find mates for threatened species.

“The SSP has known for a while about Sidney’s condition,” Thompson said. “We’ll be contacting them for a recommendation soon on new female companions for Bakari.”