10 Longest-running TV Shows

Running for 588 episodes, Lassie centered around a loyal canine companion who rescued her human family from various predicaments. Over the years, Lassie was portrayed by nine different male dogs, all descendants of the original Lassie, whose real name was Pal. During the show's run, Lassie had various owners, most notably Timmy and Jeff. Only three dogs have a star on the Hollywood Walk of Fame -- Lassie, Rin Tin Tin, and Strongheart.