Jack Hanna, a celebrity zookeeper and a director emeritus of the Columbus Zoo and Aquarium, has been diagnosed with Alzheimer’s disease and will retire from public life, according to his family.

On Wednesday, his family released a statement Jack’s Alzheimer’s disease has quickly progressed in the last few months, according to The York News-Times.

His three daughters said in a joint statement, “Dad advocated for improved wildlife habitats and focused on connecting the community with animals.”

Jack continued to be a spokesperson for the Ohio zoo until he retired in 2020. He is also well-known for his live animal demonstrations on talk shows hosted by Johnny Carson, David Letterman and, James Corden.

He always wore khakis on every TV appearance and in photos, hosting the popular syndicated TV show “Jack Hanna’s Animal Adventures” from 1993 to 2008.

The 74-year-old also hosted “Jack Hanna’s Into the Wild,” which started in 2007, and “Jack Hanna’s Wild Countdown” until last year, per The York News-Times.

The family statement also read, “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.”

His family has asked for privacy in light of COVID-19 restrictions.

The statement added, “He has spent his life connecting people and wildlife because he has always believed that having people see and experience animals is key to engaging them in more impactful conversations.” “Even though Dad is no longer able to travel and work in the same way,” the statement continued, “we know that his infectious enthusiasm has touched many hearts and will continue to be his legacy”