The Phoenix Zoo says an eight-year-old African lion named Kitambi has died after a brief illness.
Zoo officials say Kitambi passed away on Tuesday night.
He started showing signs of illness Friday when he acted lethargic and lost his appetite. Tests revealed an infection in his right rear leg and a depletion of white blood cells.
Zoo officials say Kitambi's health deteriorated rapidly despite efforts from the animal care team like IV fluids and antibiotics.
His body was transported to Midwestern University's College of Veterinary Medicine for an autopsy.
Kitambi was born at the Columbus Zoo in November 2011 and joined the Phoenix Zoo the following year. He lived with a 20-year-old female African lion named Cookie.
Zoo president and CEO Bert Castro says Kitambi will be missed.