(Well, make that actor — through the years, Lassie has actually always been played by a male dog, since male rough collies are typically larger and have fuller coats than females.)
Despite the fact that human stars usually get top billing, animals often play major parts in the success of films and TV shows — after all, what would "Mr. Ed" have been without its talking Palomino? "The Thin Man" without Asta the wire fox terrier? "National Velvet" without spirited racehorse The Pie? Nothing, that's what.
Sometimes animal actors even influence the humans they work with — actor James Cromwell has said that "I did 'Babe' and I became an animal activist." (Cromwell, a longtime vegetarian, decided to become a vegan after working with animals on the movie, which featured a smart and feisty pig who herded sheep.)
The animals on the Walk of Fame are decidedly heroic ones; one of them, Strongheart, even had a real-life record of service with the German Red Cross during World War I before he joined the ranks of the Hollywood elite. Why aren't Mr. Ed, Asta and The Pie included? Well, one assumes they're just not noble enough. It's tough to be an animal, huh?
— Lindsay Barnett, who writes about all things animals on The Times' L.A. Unleashed blog