A rare case of provoked anal penetration of an 11-year-old boy by a male German shepherd dog was confirmed by the results of morphological, serological and molecular genetic investigations. These results were of great importance to refute the suspicion on two adults. Some serious doubts remained in the version of the course of the event as presented by the boy. Some weeks later when confronted by a psychologist, the boy admitted having deliberately stimulated the dog manually and caused the animal to penetrate him.