Jack Hanna, the zookeeper and TV personality who for decades brought his love for wildlife into Americans’ homes, is struggling in his battle with Alzheimer’s, according to a new interview with his family. During his decades-long career, Hanna hosted several animal-focused TV shows, including Jack Hanna’s Into the Wild and Jack Hanna’s Wild Countdown, and was a frequent guest of David Letterman, among others. He’s also credited with elevating the profile of the Columbus Zoo, where he served as director for over 40 years, according to The Columbus Dispatch, which recently interviewed Hanna and his family. “While Dad/Jack is still mobile, his mind fails him, the light in his eyes has dimmed, and we miss who he was each & every moment of the day,” his family said in a tweet posted to Hanna’s account. Hanna's condition was first diagnosed in 2019 and came to light in 2021.