Not every dog has a high prey drive, frankly. Our Great Dane showed no interest in catching anything (from squirrels, to birds, to tennis balls), and the one time our Saint Bernard actually caught a squirrel (it was foundering in deep powdery snow, and Saints have big webbed feet that are good snowshoes ... she didn't know what to do with it, so threw it up in the air and watched it fall back down and run away!