21-Year-Old Franklin Park Zoo Lion Euthanized

BOSTON (CBS) -- One of the oldest captive lions in North America was euthanized at the Franklin Park Zoo on Thursday.

Christopher the lion was 21 years old. Zoo officials said he was put down for "quality of life reasons" after recently suffering from age-related issues, including declining kidney function, liver disease and arthritis.

"The veterinary and animal management staffs took extraordinary care of Christopher as his age-related issues mounted," said Dr. Eric Baitchman, Zoo New England Director of Veterinary Services, in a statement. "With our older animals, we do everything we can to ensure they enjoy a comfortable life as they continue to age, which is often far longer than the median life expectancy."

Lions in captivity generally live about 17 years, the zoo said.

"He was an incredible ambassador for his species and people were drawn to his impressive roar, which could be heard throughout the zoo. Perhaps the only thing more impressive than his roar was his imposing physical presence," said John Linehan, Zoo New England President and CEO, in a statement. "Christopher truly was the king of the Franklin Park Zoo."

Christopher arrived to the Franklin Park Zoo in 2001 from Lion Country Safari in Florida, where he was born.