DENVER (CBS4)– The Denver Zoo announced that its 3-year-old lion “Sango” died after he began having severe seizures last month.

The zoo said animal care and veterinary staff did everything they could to help the lion but his condition continued to decline.

The zoo determined that Sango had lost his quality of life after treatment did not resolve his liver problems or his seizures and he could not walk or even position himself to drink water.

The zoo said he was humanely euthanized on April 30.

“This is devastating for us. Our time with Sango was way too short. His condition worsened so quickly and so severely that euthanasia was our only option,” said Denver Zoo Staff Veterinarian Betsy Stringer in a statement.

Sango came to the Denver Zoo in June 2013 after he was hand-reared by zookeepers at Ellen Trout Zoo in Texas. He fathered male and female cubs Kalu and Kamara in Sept. 2016 with 3-year-old Neliah. Zookeepers say he was very playful but timid. When the cubs were born they seemed to give him confidence.

Zookeepers say he was very patient with them and allowed them to play with his mane and chased them around the yard.

The zoo said a scope showed that Sango’s liver was highly abnormal and his gall bladder was enlarged. A full animal autopsy will be conducted by veterinarians at Colorado State University.

“This is truly a tragedy. Sango was adored by staff and delighted guests. He will be dearly missed,” said Denver Zoo Vice President for Animal Care and Association of Zoos and Aquariums Lion Species Survival Plan Coordinator Hollie Colahan in a statement.

Additional Information from the Denver Zoo:

The median life span of lions in zoos is 16.8 years. In addition to Neliah and her cubs, Denver Zoo is currently home to one other adult lion, 3-year-old female Sabi.

Cards for Sango will be available for guests to sign at the Zoo’s Benson Predator Ridge exhibit