Men may have evolved to specialize in short-term “cad” and long-term “dad” mating strategies. We hypothesized that dog ownership would increase the long-term attractiveness of men, especially for cads, as this would signal nurturance and suggest tendencies for relationship commitment. Women read vignettes in an experiment with four conditions varying by male mating strategy described (dad vs. cad) and dog ownership (yes vs. no mention). Dog ownership and the dad vignette increased ratings of long-term attractiveness. Higher ratings of long-term attractiveness for cads were mediated by lower ratings of the character on tendencies for a short-term mating strategy.