Movies, scientists know, can turn us into smokers and drinkers. Now, it turns out, they also make us buy dogs. Not any old dog, of course, but the particular breed of dog that starred in last night’s feature film. To make the discovery, researchers analyzed 87 movies that featured pooches and correlated those findings with data from the American Kennel Club, which maintains a registry of more than 65 million dogs. They discovered that films can increase the popularity of the dog star’s breed for up to 10 years. The effect on dogs has been huge. For instance, the 1943 hit Lassie Come Home, a movie about a collie (as in the photo above), led to a 40% increase in collie registrations at the club. Even more dramatically, The Shaggy Dog, a 1959 movie with an Old English sheepdog as its star, doubled that breed’s registrations, the scientists report today in PLOS ONE. These days, though, movies’ influence has waned, perhaps, the researchers speculate, because of increased competition from television, the Internet, and movies themselves. Until 1940, movies with dog stars were released at a rate of less than one per year; these days, there are more than seven movies featuring dogs each year. The sudden surge in popularity hasn’t been good for the star breeds; those that became the “it” dog following their movie debuts were also overbred to meet the demand and through inbreeding have developed the greatest number of inherited disorders.