Animal and wildlife expert Jack Hanna is retiring from public life following an aggressive battle with dementia. A retired zookeeper and a director emeritus of the Columbus Zoo and Aquarium, Hanna is famous for his many appearances with his animal friends on various television shows over the years. On his official Twitter account, Hanna's daughters have announced in a statement that their father's health has greatly worsened in recent months.

"Doctors have diagnosed our dad, Jack Hanna, with dementia, now believed to be Alzheimer's disease," the statement reads. "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... Even though Dad is no longer able to travel and work in the same way, we know his infectious enthusiasm has touched many hearts and will continue to be his legacy."

The Hannas add: "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."

Though Hanna is especially beloved in Ohio, he is widely recognized for his frequent television appearances. He'd bring along animal guests for consistent appearances on late night shows hosted by the likes of Johnny Carson, David Letterman, and James Corden. He's also brought along his furry friends to daytime talk shows like Good Morning America and Maury.

Along with providing commentary on various news programs, Hanna has also done guest spots on shows like Larry King Live, Nancy Grace, and The Hollywood Squares. He also made a special guest appearance on an episode of Blue's Clues in 2003 and appeared in the 2005 music video for Neal McCoy's "Billy's Got His Beer Goggles On." Following his appearances on TV, Hanna was later given his own television programs, including Animal Adventures, Into the Wild, and Wild Countdown.

In the summer of last year, Hanna announced his retirement from serving as the director emeritus of the Columbus Zoo effective at the end of the year. His 42-year career officially came to an end on Jan. 1, 2021.

"As I approach my mid-70s with more than four decades at the Columbus Zoo, I believe it is time to wind down and officially step back while CEO Tom Stalf and the Zoo's great leadership team continue to guide the Zoo into the future. Together with many friends and partners, we've come a long way to make the world a better place for people and wildlife!" Hanna said of his retirement.

The Hanna family is asking for privacy at this time in the interest of keeping everybody safe in light of COVID-19 restrictions, though they say this is "ironic given Dad's love of interacting with people." Nevertheless, the Hannas are "grateful that the many hearts he's touched over the years are with him during this journey," as revealed in their official statement. This news comes to us from the official account for Jack Hanna on Twitter.