CINCINNATI -- Henry the hippo, the father of widely beloved baby hippo Fiona, died, the zoo announced Tuesday.
The Cincinnati Zoo & Botanical Garden euthanized Henry Tuesday morning after an exam determined his quality of life would not improve, they said in a news release
Henry had been struggling with health issues for several months, at times losing his appetite and fighting off an infection. Zoo officials previously said his kidneys had appeared to be shutting down.
In the past few days, Henry took a turn for the worse, according to the zoo. He was weak and unsteady despite positive blood work. He was becoming disoriented.
"Vets and his care team worked tirelessly to keep him comfortable and help him fight this illness," Christina Gorsuch, the zoo's curator of mammals, said. "Nothing -- antibiotics, favorite foods, extra TLC -- seemed to turn his condition around. We are all so sad to lose him."
Henry was 36, one year older than the median life expectancy for a Nile hippopotamus, according to the zoo. He came to the Dickerson Park Zoo of Springfield, Missouri, in 1982 when he was 7 months old. He "was undoubtedly the most popular animal" there, according to zoo officials. Henry was moved to the Cincinnati Zoo in 2016 for the opening of Hippo Cove as part of the Association of Zoos and Aquariums Species Survival Plan. He soon sired Fiona, his sixth, with 18-year-old Bibi.
The family of hippos became famous beyond Cincinnati when Fiona was born premature and zoo staff gave her round-the-clock care to help her grow big and healthy enough to join her parents.
"After watching Fiona fight, defy the odds and literally make history, it feels especially unfair and defeating to have to accept this outcome for Henry," Wendy Rice, the zoo's Africa head keeper, said. "While our time with him has been short in quantity, no one can deny that his quality of life before becoming ill was exceptional."
Officials weren't immediately sure what caused Henry's health to fail. Vets hope a necropsy will help them understand what happened.
Dickerson Park Zoo Director Mike Crocker said they were also saddened by Henry's death.
"It is important to remember that through the [Species Survival Plan], Henry left a legacy in Fiona," he said. "His bloodline has made a remarkable contribution to the future of the hippopotamus population."
Gorsuch said she expected Fiona and Bibi "will be fine as a bloat of two, but they will notice that he's not around and may wonder why he isn't making his contact calls."
She recalled Henry as "a sweet gentle giant with a big personality" who enjoyed interacting with caregivers and was widely loved.