Bob Barker Celebrates 90th Birthday On \"The Price Is Right\"

(Undated) -- Bob Barker is celebrating his 90th birthday with a return to the "The Price Is Right." Barker appears on today's show to help host Drew Carey spread the word about Pet Adoption Week. During his 35-year run as host of "The Price Is Right," Barker always signed off every episode of the game show reminding the audience to have their pets spayed or neutered -- a tradition Carey has continued. Since retiring from "The Price Is Right," Barker has only appeared on the show once in 2009 to promote his autobiography.