Her agent and close friend Jeff Witjas told People magazine in a statement.
At 99, she was just weeks away from celebrating her 100th birthday on Jan. 17.
"Even though Betty was about to be 100, I thought she would live forever," Witjas said. "I will miss her terribly and so will the animal world that she loved so much. I don't think Betty ever feared passing because she always wanted to be with her most beloved husband Allen Ludden. She believed she would be with him again."
CNN has reached out to Witjas for comment.
