HIS PATIENTS NEVER ASK ABOUT the movie he made, never quiz him about the "big blueberry" scene. Of course, Peter Ostrum's patients—dairy cows in Upstate New York—seem bored by anything other than grazing.

It is Ostrum's human acquaintances, particularly his 4-year-old daughter's preschool classmates, who pepper him with questions about Willy Wonka and the Chocolate Factory, the 1971 film that starred 13-year-old Ostrum as Charlie Bucket, a lucky kid touring Gene Wilder's whimsical candy plant. "For a long time, I wouldn't talk about the movie," says Ostrum, 39, a veterinarian in Lowville, N.Y. "But seeing the impact the film has on kids, I enjoy doing it now."

One obvious question: What happened to him after Wonka (rereleased this fall to mark its 25th anniversary)? "I had fun making the movie," says Ostrum, cast over thousands of aspirants, "but I wasn't convinced acting was what I wanted to do with my life." He turned down a three-picture deal and returned to his native Cleveland, where watching a vet tend to his family's horse led him to a new career. "He really liked his work, and that made a big impression on me," says Ostrum, who graduated from the Cornell College of Veterinary Medicine in 1984.

Still, Ostrum knows he'll be asked about Wonka until the bovines come home. Especially in the two-story house he shares with wife Loretta, 44, who is studying for a master's degree in education, and daughter Helenka, who loves sitting down to her father's film. "When she sees it, she says, 'That's you, Dad,' " he says, laughing. "She thinks of it as a big home movie."