05/20/2011 at 10:00 PM EDT
star Robin Tunney knew her dog had talent, but she never expected that he'd snag a plum role in her latest movie, See Girl Run
"I wanted him to get, like, a small part in it," the actress explained on The Talk
Thursday. "At the end of the rehearsal [the director] was like, 'Look, I think he should be the lead dog in the movie.' "
Tunney admits she had mixed emotions about her pup being top dog. "I don't know if I kinda got upset because I felt protective or I'm afraid I'm going to be upstaged," she said with a laugh. "And he's going to turn out to be like Benji and I'm just going to be his handler."Click above to see Tunney talk about her pup's new acting gig.See more celebrities on PEOPLEPets.com:Mario Batali Is on the Lookout for a New DogHow Nicole Richie Accidentally Took in a Pack of Stray Cats