Jack Hanna, the zoo director famous for making TV talk show appearances with live animals, has been diagnosed with dementia, his family said Wednesday.
Doctors think it is Alzheimer's disease, the family said in a statement.
"His condition has progressed much faster in the last few months than any of us could have anticipated," his daughters said.
"Sadly, Dad is no longer able to participate in public life as he used to, where people all over the world watched, learned and laughed alongside him," they said.
Hanna, 74, known as Jungle Jack, was director of the Columbus Zoo and Aquarium in Ohio, where he remains director emeritus.
He was famous for bringing animals to TV hosts like David Letterman and others, and to "Good Morning America" — where he first appeared with twin baby gorillas in 1983.
He also had TV programs of his own, Jack Hanna’s Animal Adventures, Jack Hanna’s Into the Wild and Jack Hanna’s Animal Adventures.
Hanna, who always appeared in khakis, considered the animals to be ambassadors for those in the wild.
He was hired as director of the Columbus Zoo in 1978 and retired last year. The zoo has credited him with transforming it from an "aging collection of pens and buildings" into what it is today. The zoo is often listed as among the best in the U.S.
The zoo said it was saddened to learn of the diagnosis and asked fans to join it in sending messages of support to the family.
His daughters, Kathaleen, Suzanne and Julie, wrote that their father believed that people being able to see animals led to them being more engaged in conservation efforts in the wild.
"He's always said, 'You have to touch the heart to teach the mind,'" they wrote.
Ohio Gov. Mike DeWine said he, along with the state, was sending best wishes to the family and keeping them in their prayers.
Hanna's daughters said that because of the Covid-19 pandemic they were asking for privacy, which they called ironic given their father's love of interacting with people.
"While Dad's health has deteriorated quickly, we can assure you that his great sense of humor continues to shine through," his daughters wrote. "And yes — he still wears his khakis at home."