In many Western countries, castration is the most popular surgical desexing procedure in dogs. The aim of the study was to identify the reasons for male dog castration and to determine the owners' perceptions about changes in dog behavior before and after castration. An online survey was posted on social networking sites dedicated to dogs. A total of 386 respondents participated in the survey. The main reason (39%) for castration was undesirable behavior, including hyperactivity (8%), roaming (8%), mounting (7%), aggression (5%), marking (5%) and others (5%). This surgery did not change the prevalence of aggressive behaviors towards people, but it reduced aggressive behaviors towards dogs and other animals. Castration did not reduce the presentation of anxious behavior in fearful dogs. Castration increased the number of dogs that were fearful of unfamiliar dogs/humans, as well as dogs with sound phobias, while decreased the prevalence of hiding behavior. This procedure greatly decreased incidences of roaming, mounting and urine marking as well as the dog's overall activity. Thus, it can be concluded that while castration can resolve many undesirable behaviors in male dogs, the arguments for and against neutering should always be considered on an individual basis.
Keywords: castration; desexing; dog behavior; male dogs; reasons for castration.