DENVER (AP) -- Veterinary staff at the Denver Zoo say they were forced to euthanize a 15-year-old lion named "Tawny" after discovering several critical health problems during exploratory surgery.
The Denver Post reports (http://bit.ly/WyXa0T) zookeepers noticed the South African lion had lameness in the front right leg over the past several weeks, and the feline began to refuse food during the week leading up to surgery.
A zoo news release says blood work showed Tawny was anemic, and the surgery revealed cysts on her liver that were pressing on her digestive system, making it hard to process food.
The lion, which was euthanized Wednesday, came to the zoo in May 2004 and gave birth to Saba, Sukari and Kamau the following September.
The zoo says the median lifespan of a captive lion is 16.8 years.