Many are feeling heartbroken following the announcement by Jack Hanna's family, confirming he's been diagnosed with dementia.
Hanna, 74, joined the Columbus Zoo in 1978
And he announced his retirement last year.
During his job, he became a media figure.
With regular appearances on "The Tonight Show," the "Late Show," the "Late Late Show," "Larry King Live," "The Ellen DeGeneres Show" and "Maury."
His mission? To educate the world about animals.
But today, his family has released a sad statement.
"Today, we reach out to share some personal Hanna Family news," his children, Kathaleen, Suzanne and Julie, wrote in a letter.
"Doctors have diagnosed our dad, Jack Hanna, with dementia, now believed to be Alzheimer's disease."
"His condition has progressed much faster in the last few months than any of us could have anticipated."
"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."
"Our mom — Suzi — has been by his side for 53 years in every corner of the world."
"She continues to be his rock (and ours, too)."
"We have great respect and admiration for Mom as we move through not only this difficult time with Dad, but also Julie's continued life-long challenges from her childhood leukemia, as she is currently recovering from major surgery."
"While Dad's health has deteriorated quickly, we can assure you that his great sense of humor continues to shine through. And yes — he still wears his khakis at home."
Our thoughts are with Hanna and his family.
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