Legendary Price Is Right host Bob Barker’s cause of death at 99 has been revealed as the result of a secret battle with Alzheimer’s Disease. The television icon’s death certificate said that he had suffered from progressive disease that destroys memory and other important mental functions which he had never publicly addressed before. Barker was an animal rights activist and famously ended each episode of The Price Is Right urging the audience to, ‘Help control the pet population. Have your pets spayed or neutered.’ Adam Sandler was among the first to pay tribute to the late host, taking to Instagram with a collection of photos and a heartfelt caption. Other posts remembering Barker came from fans and celebs alike, with one Twitter user writing, ‘It was exciting back then to know we could watch all of the game shows when we were sick, and Bob was the comfort in that fact.’ Bob Barker’s cause of death has been revealed as the result of a secret battle with Alzheimer’s Disease.